In a scheme a sum gives 50% of sum as compund interest. A man invested three amount for 5 years, 10 years and 15 years respectively. Find the ratio between the amount he invested if at the end he recieve same amount from all the investment?
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9 : 6 : 4
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9 : 8 : 7
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9 : 6 : 5
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9 : 8 : 2
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9 : 3 : 1
A
Correct answer
Explanation
Using CI formula A = P(1 + r)^t where r = 50% = 1/2. For equal final amounts: P1 × (3/2)^5 = P2 × (3/2)^10 = P3 × (3/2)^15. Taking ratios: P1 : P2 : P3 = (3/2)^-5 : (3/2)^-10 : (3/2)^-15. Inverting and simplifying: P1 : P2 : P3 = 2^15/3^5 : 2^20/3^10 : 2^25/3^15. Common ratio gives 9 : 6 : 4. Work backwards from equal final amounts.