Question

A certain sum becomes 3 times itself in 4 years at compound interest. In how many years does it become 27 times itself ?
A. 15 years
B. 12 years
C. 36 years
D. 21 years

Answer 1

Correct Answer - B
(i) Use formula for amount.
(ii) If `3P=P(1+(R )/(100))^(4)`, then find R.
(iii) If `27P=P(1+(R )/(100))^(n)`, then find n.