Railway Recruitment Board Mathematics — Question 1711
Question
A sum of money doubles itself in 8 years at simple interest. In how many years will it triple?
- 12
- 16
- 20
- 24
Correct answer
B — 16
Explanation (English)
Doubling means SI = P over 8 years, so rate = 100×P/(P×8) = 12.5%. Tripling needs SI = 2P → time = 100×2P/(P×12.5) = 16 years.
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