Question

A sum of money at a certain rate p.a. of simple interest doubles in the 5 years and at a different rate becomes three times in 12 years. The lower rate of interest p.a. is
(a) 20%
(b) 16⅔%
(c) 16⅓%
(d) 15½%

Answer 1

Being Simple Interest 20%*5 = 100%

while at lower rate of interest it triples in 12 years means double in 6 years ( Being Simple Interest)

100%/6 = 16.666%

Correct Answer is b = 16.66%