A sum of money triples itself in 3 years at compound interest. In how many years will it become 9 times?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 6 years
Under compound interest the amount is multiplied by the same factor in every equal period. Here that factor is 3 for every 3 years.
After 3 years: 3 times the sum
After another 3 years: \(3\times3=9\) times the sum
So the sum becomes 9 times in \(3+3=\) 6 years