alleryDoubling period under the Rule of 72 at 9% per annum approximately equals
A7 years
B8 years
C9 years
D10 years
Answer & Solution
Correct answer: B. 8 years
1. Rule of 72 gives doubling time as 72 divided by rate.
2. T = 72 / 9.
3. T = 8.
4. So a sum doubles in approximately 8 years at 9%.
_Source: ICAI BoS Foundation Paper 3, Ch 4 'Math of Finance', p.10_
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