ICSE − Q & A

Can anyone explain the time and work questions in quadratic equations

http://www.respaper.com/surya30/6601-pdf.html Q 4(b) i tried many times but i got only decimal answer pls help me out

If the rate of sales tax is 5%,Simran has to pay Rs. 7140 for the steel cupboard.What amount she has to  pay if the sales tax is increased by 2%?Plz reply ASAP....
Is the answer Rs.7276?
Do we get the final sales tax by adding 5% and 2%?

Do we have to round up when the question is asked to upto 2 decimal places?

http://www.respaper.com/anurag45/8953-pdf.html?ln=13&ov=1 Question 7:A..
With steps pls...

A boy is x years old and his mother is x^2 years old. When the lady becomes 11x years old, the boy becomes x^2 years old. Find their present ages. 
Please somebody solve this question.

suppose im given coordinates of points P and Q and i'm asking to find the equation. after finding its slope, i can take either point for finding equation right?

http://www.respaper.com/surya30/6601-pdf.html can anyone pls show me the working of  Q3a and Q3c

is there any difference between cbse and isc syllabus

i am having a confusion with the 'proceeds'. When a person sells his shares and invests the proceeds in another shares, should we include the dividend from the former shares in his second investment.