


29.
The interest on a certain deposit at 4.5% p.a. is Rs. 202.50 in one year. How much will the additional interest in one year be on the same deposit at 5% p.a.?
30.
A sum invested at 5% simple interest per annum grows to Rs. 504 in 4 years. The same amount at 10% simple interest per annum in 2 1/2 years will grow to: [C.D.S 2003]
31.
What will be the ratio of simple interest earned by certain amount at the same rate of interest for 6 years and that for 9 years? [Bank P.O. 1998]
32.
Nitin borrowed some money at the rate of 6% p.a. for the first three years, 9% p.a. for the next five years and 13% p.a. for the period beyond eight years. If the total interest paid by him at the end of eleven years is Rs. 8160, how much money did he borrow? [Bank P.O 2000]
33.
The simple interest on a sum of money will be Rs. 600 after 10 years. If the principal is trebled after 5 years, what will be the total interest at the end of the tenth year?
Answer & Solution
Answer: c) Rs. 1200
Solution: Let the sum be Rs. x. Now, S.I. = Rs. 600, T = 10 years. Rate = (100 * 600)/(x * 10) = (6000/x) % S.I. for first 5 years = Rs. (x * 5 * 6000)/(x * 100) = Rs. 300 S.I. for last 5 years = Rs. [3x * 5 * [6000/(x+100)]] = Rs. 900. Total interest = Rs. 1200. 34.
The simple interest on Rs. 10 for 4 months at the rate of 3 paise per rupee per month is:
35.
An automobile financier claims to be leading money at simple interest, but he includes the interest every six months for calculating the principal. If he is charging an interest of 10%, the effective rate of interest becomes: [N.I.F.T. 2000]
Answer & Solution
Answer: b) 10.25%
Solution: Let the sum be Rs. 100. Then, S.I. for first 6 months = Rs. (100 * 10 * 1)/(100 * 2) = Rs. 5 S.I for last 6 months = Rs. (105 * 10 * 1)/(100 * 2) = Rs. 5.25 So, amount at the end of 1 year = Rs. (100 + 5 + 5.25) = Rs. 110.25 Effective rate = (110.25  100) = 10.25% 