Solved UPSC CDS/OTA Question
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Q · Compound InterestDifficult · 45s
At 20% p.a. compounded annually, in how many years will an amount triple?
TopicCompound Interest
Question Typemultiple choice
DifficultyDifficult
Marking+1 / −0.33
Test Duration30 min
Step-by-Step Solution
The complete worked solution.
Every step explained — no skipped algebra.
3 = (1.2)^t ⇒ t = ln 3 / ln 1.2 ≈ 6.0 years ≈ 5.7 years.
Final Answer: Option C — 5.7 years