A sum of money placed at compound interest becomes three times of itself in 4 years. In how many years will it become 27 times of itself? MCQ with Answer and Explanation

Explanation:
Half-yearly rate = 16/2 = 8%. Time = 2 half-years. Amount = 20000 * (1 + 8/100)^2 = 20000 * 1.1664 = Rs. 23328. Compound Interest = 23328 - 20000 = Rs. 3328.

Explanation:
The sum doubles (2^1) in 8 years. It will become 4 (2^2) times in 2 * 8 = 16 years.

Explanation:
(1+r)³ = 8 ⇒ 1+r = 2 ⇒ r = 100%.