2021 · Q37
A sum of money compounded annually doubles itself in 5 years. In how many years will it become four times of itself ?
Elementary MathematicsSimple and Compound Interest
- A10 years
- B12 years
- C15 years
- D20 years
Explanation
If the amount doubles every 5 years under annual compounding, then after another 5 years it doubles again. Two doublings give 2 × 2 = 4 times the original. Hence it becomes four times itself in 10 years, option (a).