Question
Download Solution PDFA sum of Rs. 12,000.00 deposited at compound interest becomes double at the end of 5 years. At the end of 15 years the sum will be:
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFGiven:
Principal = Rs.12000
Time = 5 years
Formulas used:
Amount = Principal × (1 + r/100)n
Calculation:
Amount = Principal × (1 + r/100)5
⇒ 24000 = 12000 × (1 + r/100)5
⇒ 24000/12000 = (1 + r/100)5
⇒ 2 = (1 + r/100)5 (1)
⇒ At the end of 15 years,
⇒ Amount = 12000 × (1 + r/100)15
⇒ Amount = 12000 × [(1 + r/100)5 ]3 (From 1)
⇒12000 × 23
⇒12000 × 8
⇒ 96000
∴ The amount at the end of 15 years will be Rs.96000
Shortcut Trick
∴ The amount at the end of 15 years will be 8 times of 12000 = Rs.96000
Last updated on Jul 21, 2025
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