Simple interest on a certain sum at a certain rate is 9/16 of the sum. If the number representing rate per cent and time in years be equal, then the time is :

Simple interest on a certain sum at

 a certain rate is 9/16 of the sum.

 If the number representing rate per

 cent and time in years be equal, 

then the time is :

(a) 11/2 years
(b) 13/2 years
(c) 25/4 years
(d) 15/2 years

Correct answer: d

Solution :