ICSE − Q & A

Selina pg 436 : How to do part ii of Q 10B (revision paper 2)

A person invested 4455 in R100 shares at R81. He sold out R2500 worth shares when they have risen to R85 and the remaining at R78. Find the gain or loss.
R=rupees

Here we have to take 2500/ 100(NV) = 25 shares sold right? cause of we take 2500/85 the it comes in decimal points which is not possible...
Am I correct?

a) On a certain sum of money, the difference between the compound interest for a year, payable half yearly and the simple interest for a year is Rs.180. Find the sum lent out, the rate of interest in both the cases being 10% per annum.

Is it Rs. 72000?

http://www.respaper.com/deshkapanda/253/3498-pdf.html In this paper, how did you got the answer of  Question-3) b)iii) ?
(Value of BED)

Please explain.
Thanks

(x-a)(x-b) = m^2
prove that both the roots of this equation are always real.

http://www.respaper.com/anurag45/8953-pdf.html?cmd=conv The 3rd  paper is out the easiest one...

What is the probability of getting a jack of hearts from deck of 52 cards???

page 450: question 4 (b) of selina
do we have to solve it by geometry or coordinate geometry?

Find the values of K for which the equation
 36x2 + Kx + 1=0 will have imaginary roots.

How many prepared with maths? Kitne papers kiye?