A certain sum of money triples itself in 4 years at a certain rate of compound interest. In how much time the money becomes 81 times at the same rate of compound interest?
1
12 years
2
16 years
3
20 years
4
25 years
A certain sum of money triples itself in 4 years at a certain rate of compound interest. In how much time the money becomes 81 times at the same rate of compound interest?