Multiple choice

A certain sum of money kept at compound interest doubles itself in 2 years. In how many years will it become 32 times the original sum?

  1. 20 years

  2. 10 years

  3. 64 years

  4. 32 years
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If a sum doubles in 2 years, it follows the pattern 2^n. To reach 32 times (2^5), it takes 5 periods of 2 years each. 5 * 2 = 10 years.

AI explanation

Using the compound interest multiplication factor identity, if a sum doubles in 2 years, it becomes 2 times itself, which equals 2^1. To become 32 times the original sum, we set 2^(n/2) = 32, since 32 is 2^5. Equating the exponents gives n/2 = 5, which results in n = 10 years.

Keep practicing — related questions