Question

The ifference betwwen simple and compound interes on a certian sum for 2 years at 4 % per annum is rs.50 the sum is

Answer 1

Let the sum be P = Rs. 100.

time T = 2 years, rate of interest R = 6% per annum

simple interest =  PRT/100= 100*6*2/100=
Rs 12

compound amount= P( 1+R/ 100)^T
= 100*(1+6/100) ^2
= 112.36

therefore the compound interest = compound amount - principal

=112.36-100=12.36/-

the difference between the compound interest and simple interest = 12.36-12.00 = 0.36/-

if the difference between the CI and SI is Rs. 0.36 the principal = Rs. 100

if the difference between the CI and SI is Rs. 90 the principal = 100/0.36*90
= 25000

thus the sum is Rs. 25000.

hope this helps you.