Question

A man borrowed a sum of money at 5% Compound interest per annum .He repays Rs.3150 at the end of 1st year and Rs.4410 at the end of 2nd year so as to clear the entire loan. find how much rupees did he borrow?

Answer 1

First year:
Let sum be Rs. xr = 5% p.an = 1 year
I = Prn/100 = x*5*1/100 = Rs. x/20Amount = x+(x/20) = Rs. 21x/20
Second Year:
P = (21x/20)-3150 = Rs. (21x-6300)/20
I = (21x-6300)*5/(100*20) = Rs. (21x-6300)/400Amount = (21x-6300)/20+(21x-6300)/400 = (420x-126000+21x-6300)/400= Rs. (441x-132300)/400
If he pays Rs. 4410 now, he would clear off his debt.∴ Amount = Rs. 4410
=> 4410 = (441x-132300)/400=> 1764000 = 441x-132300=> 441x = 1896300=> x = Rs. 4300
Hope This Helps :)