


36.
The difference between compound interest and simple interest on an amount of Rs. 15,000 for 2 years is Rs. 96. What is the rate of interest per annum? [R.B.I. 2003]
37.
The difference between simple and compound interest compounded annually on a certain sum of money for 2 years at 4% per annum is Re. 1. The sum (in Rs.) is: [S.S.C. 2003]
38.
The compound interest on a sum of money for 2 years is Rs. 832 and the simple interest on the same sum for the same period is Rs. 800. The difference between the compound interest and the simple interest for 3 years will be:
Answer & Solution
Answer: c) Rs. 98.56
Solution: Difference in C.I. and S.I. for 2 years = Rs. 32. S.I. for one year = Rs. 400 S.I for Rs. 400 for one year = Rs. 32. So, Rate = [(100 * 32)/(400 * 1)] % = 8% Hence, difference in C.I. and S.I for 3rd year = S.I. on Rs. 832 = Rs. [(832 * 8 * 1)/100] = Rs. 66.56 Total difference = Rs. (32 + 66.56) = Rs. 98.56 39.
The difference between the simple interest on a certain sum at the rate of 10% per annum for 2 years and compound interest which is compounded every 6 months is Rs. 124.05. What is the principal sum? [S.B.I.P.O. 2000]
40.
The difference between compound interest and simple interest on a sum for 2 years at 10% per annum, when the interest is compounded annually is Rs. 16. If the interest were compounded halfyearly, the difference in two interests would be:
Answer & Solution
Answer: d) Rs. 24.81
Solution: For first year, S.I. = C.I. Now, Rs. 16 is the S.I. on S.I. for 1 year. Rs. 10 is S.I. on Rs. 100. Rs. 16 is S.I.on Rs.[(100/10) * 16] = Rs. 160 So, S.I. on principal for 1 year at 10% is Rs. 160. Principal = Rs. [(100 * 160)/(10 * 1)] = Rs. 1600 Amount for 2 years compounded half yearly = Rs. [1600 * [1 + (5/100)]^4 ] = Rs. 1944.81. C.I. = Rs. (1944.81  1600) = Rs. 344.81 S.I. = Rs. [(1600 * 10 * 2)/100] = Rs. 320 C.I.  S.I = Rs. (344.81  320) = Rs. 24.81 41.
A sum of money lent at compound interest for 2 years at 20% per annum would fetch Rs. 482 more, if the interest was payable halfyearly than if it was payable annually. The sum is:
42.
On a sum of money, the simple interest for 2 years is Rs. 660, while the compound interest is Rs. 696.30, the rate of interest being the same in both the cases. The rate of interest is: [Hotel Management, 1997]
