A sum of money triples it self in 3 years at compound interest. In how many years will it becomes 9 times.

6 years

Compounding Annually, sum of money (P) becomes 3 times in 3 years

3P = P(1+ r/100)^3

Squaring on both sides,

9P² = P²(1+ r/100)^2*3

9P = P(1+ r/100)^6

Comparing with the general equation of compound interest

Thus the amount in the condition becomes 9 times in 6 years

The correct answer is Option (2) → 6 years