Question

The difference between the compound interest (compounded annually)and simple interest on a certain sum at 10%per annum for 2yrs is rs 631. Find the sum.

Plz answer fast ...I have exam tomorrow

Answer 1

Explanation:

Let the sum be Rs. x. Then,
C.I. = x ( 1 + ( 10 /100 ))^2 - x = 21x / 100 ,
S.I. = (( x * 10 * 2) / 100) = x / 5
(C.I) - (S.I) = ((21x / 100 ) - (x / 5 )) = x / 100
( x / 100 ) = 632 * x = 63100.
Hence, the sum is Rs.63,100.

Answer 2

Given, difference between CI and SI =Rs631
rate=10%
time =2 yrs
for CI
CI=A-p
=P[(1+r/100)-1]
=P[(1+1/10)2-1]
=P[(11/10)2-1]
=P[121-100/100]
=21P/100

FOR SI
SI=PRT/100
=P*10*2/100
=P/5

CI-SI=631
21P/100-P/5=631
P/100=631
P=631*100
P=63100
So, the sum is Rs63100.

I think this answer may help you.