A sum of Rs.8,000 invested at 10% p.a. amounts to Rs.9,261 in a certain time, interest compounded half-yearly. What will be the compound interest (in Rs) on the same sum for the same time at double the earlier rate of interest, when interest is compounded annually?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e Rs.2,560.
| Understanding/Application |
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As half-yearly - r = 10/2 = 5 % Amount = Rs. 9261 p = Rs. 8000 A = p(1 + r/100)t |
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9261 = 8000(1 + 5/100)t 9261/8000 = (105/100)t (21/20)3 = (21/20)t On comparing - t = 3 years Time = 3/2 years R = 2r = 2(10) = 20% C.I. = p(1 + r/100)t - p = 8000(1 + 20/100)3/2 - 8000 = 8000(6/5)3/2 - 8000 = 10560 - 8000 = Rs. 2560 |