A sum of money doubles itself at compound interest in 15 years. In how many years it will become eight times?
A sum of money doubles itself at compound interest in 15 years. In how many years it will become eight times?
Explanation
Since the sum doubles itself in 15 years, it will quadruple (2 × 2) in 30 years (15 × 2), and become eight times (2 × 2 × 2) in 45 years (15 × 3).