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Analysis of Pupil Performance ICSE COMPUTER APPLICATIONS Research Development and Consultancy Division Council for the Indian School Certificate Examinations New Delhi Year 2018 __________________________________________________________________________________ Published by: Research Development and Consultancy Division (RDCD) Council for the Indian School Certificate Examinations Pragati House, 3rd Floor 47-48, Nehru Place New Delhi-110019 Tel: (011) 26413820/26411706 E-mail: council@cisce.org Copyright, Council for the Indian School Certificate Examinations All rights reserved. The copyright to this publication and any part thereof solely vests in the Council for the Indian School Certificate Examinations. This publication and no part thereof may be reproduced, transmitted, distributed or stored in any manner whatsoever, without the prior written approval of the Council for the Indian School Certificate Examinations. FOREWORD This document of the Analysis of Pupils Performance at the ISC Year 12 and ICSE Year 10 Examination is one of its kind. It has grown and evolved over the years to provide feedback to schools in terms of the strengths and weaknesses of the candidates in handling the examinations. We commend the work of Mrs. Shilpi Gupta (Deputy Head) of the Research Development and Consultancy Division (RDCD) of the Council and her team, who have painstakingly prepared this analysis. We are grateful to the examiners who have contributed through their comments on the performance of the candidates under examination as well as for their suggestions to teachers and students for the effective transaction of the syllabus. We hope the schools will find this document useful. We invite comments from schools on its utility and quality. Gerry Arathoon Chief Executive & Secretary October 2018 i PREFACE The Council has been involved in the preparation of the ICSE and ISC Analysis of Pupil Performance documents since the year 1994. Over these years, these documents have facilitated the teaching-learning process by providing subject/ paper wise feedback to teachers regarding performance of students at the ICSE and ISC Examinations. With the aim of ensuring wider accessibility to all stakeholders, from the year 2014, the ICSE and the ISC documents have been made available on the Council s website www.cisce.org. The documents include a detailed qualitative analysis of the performance of students in different subjects which comprises of examiners comments on common errors made by candidates, topics found difficult or confusing, marking scheme for each answer and suggestions for teachers/ candidates. In addition to a detailed qualitative analysis, the Analysis of Pupil Performance documents for the Examination Year 2018 have a component of a detailed quantitative analysis. For each subject dealt with in the document, both at the ICSE and the ISC levels, a detailed statistical analysis has been done, which has been presented in a simple user-friendly manner. It is hoped that this document will not only enable teachers to understand how their students have performed with respect to other students who appeared for the ICSE/ISC Year 2018 Examinations, but also provide information on how they have performed within the Region or State, their performance as compared to other Regions or States, etc. It will also help develop a better understanding of the assessment/ evaluation process. This will help teachers in guiding their students more effectively and comprehensively so that students prepare for the ICSE/ ISC Examinations, with a better understanding of what is required from them. The Analysis of Pupil Performance document for ICSE for the Examination Year 2018 covers the following subjects: English (English Language, Literature in English), Hindi, History, Civics and Geography (History and Civics, Geography), Mathematics, Science (Physics, Chemistry, Biology), Commercial Studies, Economics, Computer Applications, Economic Applications, Commercial Applications. Subjects covered in the ISC Analysis of Pupil Performance document for the Year 2018 include English (English Language and Literature in English), Hindi, Elective English, Physics (Theory), Chemistry (Theory), Biology (Theory), Mathematics, Computer Science, History, Political Science, Geography, Sociology, Psychology, Economics, Commerce, Accounts and Business Studies. I would like to acknowledge the contribution of all the ICSE and the ISC examiners who have been an integral part of this exercise, whose valuable inputs have helped put this document together. I would also like to thank the RDCD team of, Dr. M.K. Gandhi, Dr. Manika Sharma, Mrs. Roshni George and Mrs. Mansi Guleria who have done a commendable job in preparing this document. Shilpi Gupta Deputy Head - RDCD October 2018 ii CONTENTS Page No. FOREWORD i PREFACE ii INTRODUCTION 1 QUANTITATIVE ANALYSIS 3 QUALITATIVE ANALYSIS 10 INTRODUCTION This document aims to provide a comprehensive picture of the performance of candidates in the subject. It comprises of two sections, which provide Quantitative and Qualitative analysis results in terms of performance of candidates in the subject for the ICSE Year 2018 Examination. The details of the Quantitative and the Qualitative analysis are given below. Quantitative Analysis This section provides a detailed statistical analysis of the following: Overall Performance of candidates in the subject (Statistics at a Glance) State wise Performance of Candidates Gender wise comparison of Overall Performance Region wise comparison of Performance Comparison of Region wise performance on the basis of Gender Comparison of performance in different Mark Ranges and comparison on the basis of Gender for the top and bottom ranges Comparison of performance in different Grade categories and comparison on the basis of Gender for the top and bottom grades The data has been presented in the form of means, frequencies and bar graphs. Understanding the tables Each of the comparison tables shows N (Number of candidates), Mean Marks obtained, Standard Errors and t-values with the level of significance. For t-test, mean values compared with their standard errors indicate whether an observed difference is likely to be a true difference or whether it has occurred by chance. The t-test has been applied using a confidence level of 95%, which means that if a difference is marked as statistically significant (with * mark, refer to t-value column of the table), the probability of the difference occurring by chance is less than 5%. In other words, we are 95% confident that the difference between the two values is true. t-test has been used to observe significant differences in the performance of boys and girls, gender wise differences within regions (North, East, South and West), gender wise differences within marks ranges (Top and bottom ranges) and gender wise differences within grades awarded (Grade 1 and Grade 9) at the ICSE Year 2018 Examination. The analysed data has been depicted in a simple and user-friendly manner. 1 Given below is an example showing the comparison tables used in this section and the manner in which they should be interpreted. The table shows comparison between the performances of boys and girls in a particular subject. The t-value of 11.91 is significant at Comparison on the basis of Gender Gender Girls Boys *Significant at 0.05 level N 2,538 1,051 Mean 66.1 60.1 SE 0.29 0.42 t-value 11.91* 0.05 level (mentioned below the table) with a mean of girls as 66.1 and that of boys as 60.1. It means that there is significant difference between the performance of boys and girls in the subject. The probability of this difference occurring by chance is less than 5%. The mean value of girls is higher than that of boys. It can be interpreted that girls are performing significantly better than boys. The results have also been depicted pictographically. In this case, the girls performed significantly better than the boys. This is depicted by the girl with a medal. Qualitative Analysis The purpose of the qualitative analysis is to provide insights into how candidates have performed in individual questions set in the question paper. This section is based on inputs provided by examiners from examination centres across the country. It comprises of question wise feedback on the performance of candidates in the form of Comments of Examiners on the common errors made by candidates along with Suggestions for Teachers to rectify/ reduce these errors. The Marking Scheme for each question has also been provided to help teachers understand the criteria used for marking. Topics in the question paper that were generally found to be difficult or confusing by candidates, have also been listed down, along with general suggestions for candidates on how to prepare for the examination/ perform better in the examination. 2 QUANTITATIVE ANALYSIS STATISTICS AT A GLANCE Total Number of Candidates: 1,09,005 Highest Marks: 100 Mean Marks: Lowest Marks: 03 83.5 3 PERFORMANCE (STATE-WISE & FOREIGN) West Bengal 82.7 Uttarakhand 83.9 Uttar Pradesh 81.7 Tripura 83.1 Telangana 82.9 Tamil Nadu 87.0 Sikkim 75.5 Rajasthan 82.7 Punjab 82.5 Puducherry 74.3 Odisha 82.9 New Delhi 93.4 Meghalaya 83.9 Maharashtra 88.7 Madhya Pradesh 79.1 Kerala 87.8 Karnataka 86.8 Jharkhand 82.2 Himachal Pradesh 82.1 Haryana 87.0 Gujarat 81.6 Goa 91.8 Chhattisgarh 76.4 Chandigarh 91.8 Bihar 85.1 Assam 84.7 Andhra Pradesh 80.8 Foreign 89.3 The States/UTs of New Delhi, Goa and Chandigarh secured highest mean marks. Mean marks secured by candidates studying in schools abroad were 89.3. 4 GENDER-WISE COMPARISON GIRLS BOYS Mean Marks: 83.9 Mean Marks: 83.1 Number of Number of Candidates: 46,840 Candidates: 62,165 Comparison on the basis of Gender Gender Girls Boys N Mean SE t-value 46,840 62,165 83.9 83.1 0.06 0.06 9.03* *Significant at 0.05 level Girls performed significantly better than boys. 5 REGION-WISE COMPARISON East North Mean Marks: 82.8 Mean Marks: 81.9 Number of Candidates: 36,258 Number of Candidates: 41,475 Highest Marks: 100 Lowest Marks: 28 Highest Marks: 100 Lowest Marks: 03 Mean Marks: 85.8 REGION Number of Candidates: 22,173 Highest Marks: 100 Lowest Marks: 40 South Mean Marks: 87.3 Number of Candidates: 8,838 Mean Marks: 89.3 Number of Candidates: 261 Highest Marks: 100 Lowest Marks: 44 Foreign 6 Highest Marks: 100 Lowest Marks: 31 West Mean Marks obtained by Boys and Girls-Region wise 89.3 87.6 86.3 82.3 83.1 81.6 North 89.4 87.1 85.3 82.6 East South West Foreign Comparison on the basis of Gender within Region Region North (N) East (E) South (S) West (W) Foreign (F) Gender Girls Boys Girls Boys Girls Boys Girls Boys Girls Boys *Significant at 0.05 level N Mean SE 17,367 24,108 15,002 21,256 10,916 11,257 3,437 5,401 118 143 82.3 81.6 83.1 82.6 86.3 85.3 87.6 87.1 89.3 89.4 0.10 0.09 0.11 0.10 0.10 0.12 0.21 0.18 1.12 1.12 REGION (N, E, S) 7 t-value 4.99* 2.90* 6.01* 1.81 -0.07 MARK RANGES : COMPARISON GENDER-WISE Comparison on the basis of gender in top and bottom mark ranges Marks Range Top Range (81-100) Bottom Range (0-20) *Significant at 0.05 level Gender Girls Boys Girls Boys N Mean SE 30,274 39,012 0 2 92.0 92.7 0 5 0.03 0.03 0 2 Boys Marks Range (81-100) Girls t-value -15.22* - All Candidates 92.7 81 - 100 92.0 92.4 71.2 61 - 80 71.8 71.5 Marks Range (81-100) 54.8 41 - 60 55.4 55.0 36.8 21 - 40 36.8 36.8 5.0 0 - 20 5.0 8 GRADES AWARDED : COMPARISON GENDER-WISE Comparison on the basis of gender in Grade 1 and Grade 9 Grades Grade 1 Grade 9 *Significant at 0.05 level Gender Girls Boys Girls Boys N Mean SE 19,945 27,429 0 2 95.5 95.8 0 5.0 0.02 0.02 0 2.00 Boys Grade 1 Girls t-value -10.31* - All Candidates 95.8 95.5 95.7 1 84.8 84.8 84.8 2 75.6 75.7 75.7 3 66.7 66.9 66.8 4 Grade 1 57.3 57.5 57.4 5 48.5 48.5 48.5 6 41.1 40.7 41.0 7 30.0 31.0 30.1 8 9 9 5.0 5.0 QUALITATIVE ANALYSIS SECTION A (40 Marks) Attempt all questions Question 1 (a) Define abstraction. [2] (b) Differentiate between searching and sorting. [2] (c) Write a difference between the functions isUpperCase( ) and toUpperCase( ). [2] (d) How are private members of a class different from public members? [2] (e) Classify the following as primitive or non-primitive datatypes: [2] (i) char (ii) arrays (iii) int (iv) classes 10 Comments of Examiners (a) Many candidates, instead of writing the definition of abstraction, wrote the definition of encapsulation Some candidates did not write important keywords like hiding the background details or showing the essential details. (b) Some candidates wrote the types of searching and sorting instead of their differences based on Java programming. A few candidates used the same words as given in the question i.e. searching means to search something and sorting means sorting data. (c) Majority of the candidates were not clear about the difference between Character class functions and String functions. Most of the candidates were not aware that isUpperCase() happens to be a Character class function. (d) Majority of the candidates wrote very general answers like- can be seen by everyone or shown to or used by everyone or public premises or cannot be seen by everyone or only user can see or use, or everything is not shown or private premises. (e) Most of the candidates were able to answer this question. However, a few candidates got confused between primitive and non-primitive data types. 11 Suggestions for teachers - Explain in detail with relevant examples, the basic principles of Oops and difference between them. - Emphasize the importance of the keywords in the definitions and stress on their usage while writing the definitions. - Explain to the students, the meaning of and the difference between the terms searching and sorting as a concept to be used in programming with illustrations. - Teach the different Character functions and String functions with examples - Encourage the students to use different functions in programming. - Program segments with library functions to write the output or return data type or purpose or questions will improve their learning. - Ensure that students understand the meaning of all technical terms and their use. - Train students to write the answers as per Java, rather than writing general meaning of the terms. - Explain primitive and non-primitive data types with examples. Also give sufficient practice to the students on questions based on data types MARKING SCHEME Question 1 (a) abstraction: the act of representing essential features and hide unnecessary or background details is called abstraction. (b) Searching Sorting To find an element in an array is To arrange the elements in an order called searching. is called sorting. (c) isUpperCase toUpperCase CHECKS whether a given character CONVERTS the character to its is an uppercase letter or not upper case Output of this function is boolean (d) Output of this function is character. public members can be accessed from any other class. private members can only be accessed within the declared class. (e) char primitive array non-primitive int primitive class non primitive Question 2 (a) (i) int res = 'A'; [2] What is the value of res? (ii) Name the package that contains wrapper classes. (b) State the difference between while and do while loop. [2] (c) System.out.print("BEST "); [2] System.out.println("OF LUCK"); Choose the correct option for the output of the above statements (i) BEST OF LUCK (ii) BEST OF LUCK (d) Write the prototype of a function check which takes an integer as an argument and returns a character. 12 [2] (e) Write the return data type of the following function. (i) endsWith() (ii) log() [2] Comments of Examiners (a) (i) Majority of the candidates wrote the answer as A or A or A. Candidates were unable to understand the implicit conversion. (ii) Most of the candidates were able to answer this question. However, some candidates wrote io or util as the answer while a few candidates wrote the answer Lang or in capital letters LANG. (b) Most of the candidates were able to answer this question. However, some candidates interchanged the answers. (c) Majority of the candidates were unable to select the correct option for the output of the given statements as either they seemed to be unclear of the working of the println() method or did not read all the options carefully. (d) Several candidates could not write the prototype of the function given in the question. (e) (i) Many candidates, instead of writing Boolean, wrote return type as String. (ii) Many candidates wrote return type as float or integer. Some candidates mentioned data types with the first letter in uppercase. 13 Suggestions for teachers - Explain type of conversions, explicit and implicit, with examples especially character type to integer type and ASCII code and vice-versa. - Ensure that all concepts of the lesson on wrapper classes are clear to the students. - Explain the concept of while and teach this concept with output printing questions. - Clarify the working of println() method explicitly. - Give practice to the students in the computer lab, of print() and println() methods, with ample examples. - Explain to the students the purpose of prototype and every segment of the prototype clearly Ensure that the students have understood the data types of the parameters While teaching in-built functions, ensure that return data type of each function, whether mathematical or character or string, has been explained, with examples, to th students Explain the difference between the data types and the wrapper classes with examples. MARKING SCHEME Question 2 (a) (i) 65 (ii) lang (b) while loop do while loop Entry controlled loop Exit controlled loop If condition is false in the beginning Loop will execute at least once even loop never executes, if the condition is false. minimum repetition is 0 (c) (i) BEST OF LUCK (d) char check (int n) (e) (i) boolean (ii) double minimum repetition is 1 Question 3 (a) (b) Write a Java expression for the following: [2] 3 + 2 + What is the value of y after evaluating the expression given below? [2] y+= ++y + y-- + -- y; when int y=8 (c) Give the output of the following: (i) Math.floor (-4.7) (ii) Math.ceil(3.4) + Math.pow(2, 3) [2] (d) Write two characteristics of a constructor. [2] (e) Write the output for the following: [2] System.out.println("Incredible"+"\n"+"world"); (f) Convert the following if else if construct into switch case if( var==1) System.out.println("good"); 14 [2] else if(var==2) System.out.println("better"); else if(var==3) System.out.println("best"); else System.out.println("invalid"); (g) (h) Give the output of the following string functions: (i) "ACHIEVEMENT".replace('E', 'A') (ii) "DEDICATE".compareTo("DEVOTE") Consider the following String array and give the output [2] [2] String arr[]= {"DELHI", "CHENNAI", "MUMBAI", "LUCKNOW", "JAIPUR"}; System.out.println(arr[0].length()> arr[3].length()); System.out.print(arr[4].substring(0,3)); (i) Rewrite the following using ternary operator: [2] if (bill >10000) discount = bill * 10.0/100; else discount = bill * 5.0/100; (j) Give the output of the following program segment and also mention how many times the loop is executed: int i; for ( i = 5 ; i > 10; i ++ ) System.out.println( i ); System.out.println( i * 4 ); 15 [2] Comments of Examiners (a) Majority of the candidates did not put the parenthesis in the denominator. Some candidates were not familiar with the syntax of sqrt function. (b) Many candidates seemed to be unaware of the meaning of y+=. Most candidates made errors while evaluating prefix and post fix operators. In many answer scripts, addition of the initial value of the variable to the evaluated value of the expression was incorrect. Some candidates added the decremented value to the evaluated value of the expression. (c) (i) Several candidates did not write the negative sign in the answer. Many students did not write the answer in decimals. Some candidates, instead of writing the answer as -5 0, wrote it as - 4 or - 4 0 or 4 0. (ii) Most of the candidates wrote 12 as the answer instead of 12 0. (d) Majority of the candidates were able to answer this question. However, some candidates wrote that constructor is used to construct objects, or it is used to make the program easier. (e) Several candidates simply copied the question. Majority of the candidates were not clear of the use of \n. The common errors made by the candidates were: Incredible \n world, Incredible + \n + world . (f) Many candidates wrote if with in case. The common errors made by majority of the candidates were: (i) Case 1: if (var==1) or var==1. (ii) Switch var( ); or switch was missing. (iii) Break and default statements were missing. 16 Suggestions for teachers - While explaining the hierarchy of operators to the students, lay stress on the importance of parenthesis, with the help of appropriate examples. - Emphasize on the importance of short hand notation. - Guide students how to evaluate prefix/postfix notation. - Explain the addition of the initial value of the variable to the evaluated value of the expression in such expressions. - Explain the difference between y+= <expression> and y= < expression>. - Give adequate practice to the students of expressions with Math functions. - Encourage students to execute and see the outputs practically. - Teach, with examples, the definition of constructor and its characteristics. - Clarify Escape sequence and its working with sufficient number of examples. - Demonstrate on the computer, the effect of the escape sequence on the output. - Interpret to the students the difference between switch and if () statement. (g) (i) Majority of the candidates were able to answer this question. However, in a few answer scripts only the first occurrence of E was converted. (ii) Majority of the candidates were unclear about the working of compareTo() function. Several candidates were unable to calculate ASCII difference. In a few answer scripts, the answer calculated was either 18 or -1. Some candidates wrote any random negative value as the answer. (h) Some candidates, instead of writing false as the answer, wrote 5>6. Some candidates were unclear whether the position of second argument was included in the output or not. Some candidates extracted the character at third index also. (i) The common errors made by majority of the candidates were: (i) if(bill>10000)? bill*10.0/100: bill*5.0/100. (ii) The assignment part of the statement was not being written. (iii) discount = - not being written. (j) Majority of the candidates were unable to identify the final limit of the loop. Some candidates wrote error in the condition of the loop. - Give adequate practice in conversion of if to switch and vice-versa. - Discuss with the students, examples of various problems with the appropriate conditional statements. - Explain String functions with examples. - Theoretically and through practical sessions, explain the execution of the compareTo() function, so that the students understand the difference between equals() and compareTo() functions. - Explain the importance of ASCII values of the letters (both uppercase and lowercase) to evaluate the output value. - Clarify to the students how relational operators works in output statement and results as true or false. - Practically show to the students how to extract the number of characters in substring function. - Interpret clearly the purpose and the working of the second argument in substring() function. - Explain to the students that ? represents if and: represents else. - Make the students practice conversion from if- else to ternary and ternary to if- else in the class. - Explain all the variations of for loop. - Teach loops with different initial and final values and their output after execution. MARKING SCHEME Question 3 (a) . (3 + )/( + ) OR Math.sqrt(3*x+Math.pow(x,2))/(a+b); (b) 33 (c) i. -5.0 ii. 12.0 17 (d) (e) (i) Constructors have the same name as that of the class they belong to. (ii) Constructors are executed when an object is created. Incredible world (f) switch(var) { case 1: case 2: case 3: default: System.out.println("good"); break; System.out.println("better"); break; System.out.println("best"); break; System.out.println("invalid"); } (g) (h) (i) ACHIAVAMANT (ii) -18 (i) false (ii) JAI (i) discount = bill>1000? bill*10.0/100: bill *5.0/100; (j) Output: 20 Loop is not executed even once SECTION B (60 Marks) Attempt any four questions from this Section Question 4 Design a class RailwayTicket with following description: Instance variables/data members : String name : String coach : long mobno : To store the name of the customer To store the type of coach customer wants to travel To store customer s mobile number 18 [15] int amt : To store basic amount of ticket int totalamt : To store the amount to be paid after updating the original amount Member methods : void accept () To take input for name, coach, mobile To update the amount as number and amount. void update () per the coach selected (extra amount to be added in the amount as follows) Type of Coaches Amount First_AC Second_AC 700 500 Third_AC 250 sleeper None void display () To display all details of a customer such as name, coach, total amount and mobile number. Write a main method to create an object of the class and call the above member methods. Comments of Examiners Numerous types of errors were committed in this question by many candidates, namely: Suggestions for teachers - Used a different class name other than the one given in - Train students to write programs the question. involving multiple functions. - Variable declaration was done at many places i.e. Explain the difference between global immediately after class and also inside accept() and local variables and how to use - Function names and variable names were different from them in different functions in a the ones asked in the question. program. - The totalamt which was to be calculated was accepted - How to create an object and invoke the from the user. function using the object needs to be - Update() function. explained thoroughly and practised - Syntax error while writing input statement e.g. nextInt() properly. - which letter to be written in capital. - While comparing types of coaches, words were not written within double quotes. - Calculation of extra amount. - Syntax errors in the object creation and function call statement. 19 MARKING SCHEME Question 4 import java.util.*; class RailwayTicket { String name, coach; long mobno; int amt ,totalamt; void accept() { Scanner sc = new Scanner(System.in); System.out.println("enter name , coach and mobile no and amount"); name=sc.next(); coach=sc.next(); mobno=sc.nextLong(); amt=sc.nextInt(); } void update() { if(coach. equalsIgnoreCase ("First_AC")) totalamt=amt+700; STEPS else if(coach. equalsIgnoreCase ("Second_AC")) class name totalamt=amt+500; Variable declaration else if(coach. equalsIgnoreCase ("Third_AC")) void accept () totalamt=amt+250; Four inputs else totalamt=amt; void update() } Four conditions and calculations void display() { System.out.println("name is :"+name); void display () System.out.println("mobile no is :"+mobno); Output (totalamt compulsory) System.out.println("coach is :"+ coach); Object creation with one function call System.out.println("total amount is :"+totalamt); } Variable description/Mnemonic codes public static void main (String arg[]) { RailwayTicket ob =new RailwayTicket(); ob.accept(); ob.update(); ob.display(); }} 20 Question 5 [15] Write a program to input a number and check and print whether it is a Pronic number or not. (Pronic number is the number which is the product of two consecutive integers) Examples: 12 = 3 4 20 = 4 5 42 = 6 7 Comments of Examiners Many candidates answered this question correctly. Some common errors observed were: - Output in most cases was written inside the loop and the break and flag statements were not written. - Not a pronic number was not printed, - In the if condition, instead of (i*((i+1)==num), (i*i+1==num) was written. - In the if statement, instead of the relational operator (==), assignment operator (=) was used. - Mentioning that else statement inside the loop results in printing both the statements Pronic Number and also Not a pronic number . Suggestions for teachers 21 Train students about the use of for loop. Give sufficient practice on problems to print an appropriate output message. Explain Operator precedence and importance of use of parenthesis in proper place. The effect of not putting parenthesis should be shown on the computer. Teach students the use of break statement to come out of the loop. Advice the students to read the questions carefully. MARKING SCHEME Question 5 import java.util.*; class pronic { public static void main(String arg[]) { Scanner sc = new Scanner(System.in); System.out.println("enter the number"); int num=sc.nextInt(); int flag=0; for(int i=0;i<num;i++) { if( i*(i+1)==num) { flag=1; break; } } if(flag==1) System.out.println("Pronic number"); else System.out.println("Not a pronic number"); } } Alternate method class Q5 { public void pronic (int n) { int s=(int)Math.sqrt(n); if(s*(s+1)==n) System.out.println(n +" is a pronic number"); else System.out.println(n+" is not a pronic number "); } } Variable description STEPS Input flag initialisation for loop if condition flag=1 Jump statement break if else and displaying message Variable description/Mnemonic codes 22 [15] Question 6 Write a program in Java to accept a string in lower case and change the first letter of every word to upper case. Display the new string. Sample input: we are in cyber world Sample output: We Are In Cyber World Comments of Examiners Majority of the candidates were unable to answer this question correctly. Some of the commonly made mistakes were: - Not taking care of the index of charAt() or substring() function. - Incorrect initial and final values of the for loopforr(int i=1; i<=l;i++). - Accessing first character after space was done by writing (ch+1). - Converting the first character after space was done as: ch.toUpperCase() or (ch+1).toUpperCase() - Displaying output without space between the words. - Getting an incorrect output as only the first character was converted and displayed. Suggestions for teachers Illustrate to the students that in the String, since position starts with 0, so condition should be either i< s.length() or i<=s.length()-1. Explain practically to the students how to access character after space. Give adequate number of exercises on String and Character functions to avoid confusion with the students when they use it in the program. MARKING SCHEME Question 6 import java.util.*; class ques6 { public static void main(String args[]) { Scanner obj= new Scanner(System.in); String s=""; System.out.println(" enter a string"); String sen=obj.nextLine(); sen=' ' +sen; int l= sen.length(); for(int x= 0; x<l; x++) { char ch= sen.charAt(x); if (ch==' ') { 23 int i= sen.charAt(x+1); i=i-32; s= s+ ' '+ (char)i; x++; } else s=s+ch;} System.out.print(s); }} Alternate Method // To change the first letter of each word to uppercase import java.util.*; class Q6_Title_Case { public static void main(String args[]) { Scanner sc= new Scanner(System.in); String sent,x=""; char k , p ; int len, i; System.out.print("Enter a sentence"); sent= sc.nextLine(); sent= sent.toLowerCase(); sent= " " + sent; len = sent.length(); for(i=0;i<len-1;i++) { k=sent.charAt(i); p=sent.charAt(i+1); if(k==' ' && p!=' ') p=Character.toUpperCase(p); x=x+p; } System.out.println("The new string is "+ x); } } Alternate Method class change { void change( String s) { int l=s.length(),p,i; String str=""; s=s.toLowerCase(); s=s+" "; for(i=0;i<l;i++) { 24 STEPS Input Declaration of variable Finding length Logic Output Variable description/Mnemonic codes p=s.indexOf(" ",i); str=s.substring(i,p); System.out.print(Character.toUpperCase(str.charAt(0))+str.substring(1)+" "); i=p; }}} [15] Question 7 Design a class to overload a function volume() as follows: (i) double volume (double R) with radius (R) as an argument, returns the volume of sphere using the formula. V = 4/3 22/7 R3 (ii) double volume (double H, double R) with height(H) and radius(R) as the arguments, returns the volume of a cylinder using the formula. V = 22/7 R2 H (iii) double volume (double L, double B, double H) with length(L), breadth(B) and Height(H) as the arguments, returns the volume of a cuboid using the formula. V=L B H 25 Comments of Examiners Most candidates answered correctly. However, a few general mistakes were observed in all the three functions: - - - Declaration of the variable V, was missing. Void was used in the prototype, but return statement was used in the body of the function. Double was used in the prototype, but System.out.println() was used in the body of the function and return statement was missing. Void with System.out.println() was used. Though it shows no error, the combination is not as per the requirement in the question. In the keyword return R was capital. In the formula, instead of R*R*R, R3 was written. Function name was not as per the question. Function overloading concept was not followed. Three different functions with different names were used. 26 Suggestions for teachers - Explain the topic on Functions with the various ways in which the functions can be used, step-by-step without passing arguments; with arguments; without return data type and return statement; using return data type and return statement. - Illustrate basic syntax of function in detail such as when void return type is mentioned, the function has to have output statement in the function and when, instead of void, any other data type is written then return jump statement should be there in function. - Teach the concept of rules of function overloading. - Lay stress on writing keyword return, in small case. Instruct students to place proper operators while writing Java expression in the program MARKING SCHEME Question 7 import java .io.*; public class mensuration STEPS { 3 Functions with correct argument double volume(double R) Formulas in all the 3 functions { double V= 4.0/3* 22.0/7*Math.pow(R,3); return statements in all the 3 functions return(V); Variable description/Mnemonic codes } double volume( double H,double R) { double V= 22.0/7 * Math.pow(R,2) *H; return(V); } double volume( double L, double B , double H) { double V = L*B*H; return( V); } } Question 8 [15] Write a menu driven program to display the pattern as per user s choice. Pattern 1 Pattern 2 ABCDE B ABCD LL ABC UUU AB EEEE A For an incorrect option, an appropriate error message should be displayed. 27 Comments of Examiners Majority of the candidates attempted well barring a few exceptions who showed following lapses: - Menu was not displayed. - Input for choice was not taken. - Pattern printing was done using multiple print statements. - Nested loop logic was not used, - To start with new line,println( ) was missing,. - ASCII value was used to print ABCDE but was not converted properly. (Loop value started with 65 and was checked for <= 69, but conversion to character was incorrect). - Two separate classes were written instead of one. - In the statements, switch and default. first character s and d were in capital letters. Suggestions for teachers Give sufficient practice for writing menu driven programs. programs on pattern printing and series calculation which require nested looping. Teach problems involving conversion of character to its ASCII value and vice-versa. Give adequate practice of nested for loop, show the working and effect on the output when condition is changed. i.e. instead of < when > sign is used. Allow students to do lot of programs with String and nested for and show output on the computer when println() is missing. Provide adequate practice to the students on Syntax of switch case. Lay stress on keywords, which have to be written in small case. MARKING SCHEME Question 8 import java .util.*; class series { public static void main(String arg[]) { Scanner sc = new Scanner(System.in); System.out.println("1.Series1 2.series2"); System.out.println("enter the choice"); int choice=sc.nextInt(); switch(choice) { case 1:String s="ABCDE"; for(int i=s.length();i>0;i ) { STEPS Displaying menu, input choice, switch Initialising/ input string in case 1 for loop with length of string Display and substring function Initialising string in case 2/Input Outer for loop Inner for loop Extraction , and display println() Default Variable description/Mnemonic codes 28 System.out.println(s.substring(0,i)); } break; case 2 :String s1="BLUE"; for(int i=0;i<s1.length();i++) { for(int j=0;j<=i;j++) { System.out.print(s1.charAt(i)); } System.out.println(); } break; default :System.out.println("invalid choice"); } } } Question 9 [15] Write a program to accept name and total marks of N number of students in two single subscript array name[ ] and totalmarks[ ]. Calculate and print: (i) The average of the total marks obtained by N number of students. [average = (sum of total marks of all the students)/N] (ii) Deviation of each student s total marks with the average. [deviation = total marks of a student average] Comments of Examiners Most of the candidates wrote the program correctly. However, a few could not attempt it correctly due to following miscues: - Value of N (size of the array) was taken after arrays, name and total marks were created - While accepting the values into the array, the index number was missing. Instead of name[i], candidates wrote name[]= sc.next(). - All operations i.e. input, calculating an average and deviation was done in one Loop. - The average of the total marks obtained by N number of students was calculated inside for loop. - Deviation of each student s total marks with average marks was not Displayed, rather it was printed outside for loop. 29 Suggestions for teachers - Allow plentiful practice on Array creation with different data types. - Give sufficient practice of using array concept, accepting the values into the array, and printing the values from the array. - Clarify the concept of array index. - Teach using arrays, not only searching and sorting techniques but other general programs like, billing for many customers, pay slips for many employees etc. MARKING SCHEME Question 9 import java .io.*; import java.util.*; class ques9 { public static void main(String aa[]) { Scanner obj = new Scanner(System.in); int n; System.out.println("enter number of students"); n= obj.nextInt(); String name[] = new String[n]; double marks[] = new double[n]; double ave, total=0.0; for(int x=0; x<n; x++) { System.out.println(" enter name and totalmarks"); name[x]= obj.nextLine(); marks[x]= obj.nextDouble(); total=total+ marks[x]; } ave= total/n; System.out.println("Name " + " " + " Deviation"); for(int x= 0; x<n;x++) System.out.println( (marks[x] ave)); } } 30 STEPS Accepting n, total=0.0 Declaring two array Loop Accepting value in array total=total + marks ave = total/n Output headings, loop for output Output with calculation deviation Variable description/Mnemonic codes Topics found difficult/ confusing by candidates Suggestions for candidates Library functions - its appropriate use. Arrays used with commercial / calculation-based programs. Menu driven program with pattern printing. Identifying the return data type of the library functions-print( ) and println( ) Confusion in the use of print() and println() functions. Conversion of if-else if to switch-case Output questions. CompareTo() function and its working. Syntax of switch-case and array declaration and initialization. Pattern printing using nested loop. String and Character functions. Return a value from a user-defined function. Using the key terms in definitions while writing the differences. Output of Math.floor() of negative values. Post increment and shorthand assignment operator. How to convert first character of a word to uppercase after space. Revise and integrate the concepts studied in Class IX with the Class X syllabus. Avoid selective study. Give equal importance to all the topics mentioned in the syllabus. Practise each topic/sub topic with as many examples as possible. Being an application-oriented subject, apply what is taught in the program and explain its outcome. Give sufficient practice to output-based questions. Understand all key terms and definitions comprehensively and learn. Learn correct use of all statements to eliminate syntax errors. Practise programs on various types of loops, their working, conversion from one loop to another and working of nested loop. Use proper variable names and ensure that every program has a variable description table. Avoid writing abbreviations like SOP, SOPLN, PSVM. Understand the logic of a program instead of memorising it. Explain programs using Mnemonic variables and comments. After writing the program, dry run it with different inputs. Write variable description /Mnemonic codes for every program. Practise previous years ICSE question papers, Read the questions carefully and write the answers according to their requirements. Utilize the reading time to clearly understand the nature of the question. 31
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