# If the simple interest on a certain sum of money is 4/25 of the sum and the rate percent equals the number years, then the rate of interest per annum is ?

If the simple interest on a certain sum of money is 4/25 of the sum and the rate percent equals the number years, then the rate of interest per annum is ?

A. 4 %

B. 5 %

C. 8 %

D. 10 %

**Answer : **A. 4 %...

## Explanation :

Let the principal be Rs.x, then the simple interest (I) = (4 / 25 )x.

The rate of interest per annum be r% then time (T) = r years

R = ( 100 * I ) / ( P * T )

r = ( 100 * ( 4/25 ) x ) / ( x * r )

r^{2} = 400 / 25

r = 20 / 5

= 4 %