Question

If the simple interest on a certain sum of money for 3 years is three-tenth of the sum , then find the rate of interest per annum.​

Answer 1

Suppose :

Sum = P

Rate = R %

Time = 3 years.

Hence :

3PR / 100 = 3/ 10 P.

Cancelling P,  

R / 100 = 1/ 10

=> R = 10 %

Hence the answer is that the rate of interest per annum is 10%.