# S.I. & C.I. (24)

1. The difference between simple and compound interests compounded annually on a certain sum of money for 2 years at 4% per annum is Rs 1. Find the sum
1. Rs 600
2. Rs 625
3. Rs 650
4. Rs 675
5. None of these

Explanation :-

The difference between CI and SI on Rs. P for 2 years at R% per annum P*(R/100)^2
P(R/100)^1,
P(4/100)^1
P(1/25)^1
P(1/6251
625

2. On a sum of money, simple interest for 2 years is Rs 660 and compound interest is Rs 696.30, the rate of interest being the same in both cases.
1. 8%
2. 9%
3. 10%
4. 11%
5. None of these

Explanation :-

Difference in C.I and S.I for 2 years = Rs(696.30-660) = Rs. 36.30.
S.I for 1 year = Rs. 660/2 = Rs. 330.
S.I on Rs.330 for 1 year = Rs. 36.30
R% of 330 = Rs. 36.30
R = (36.30/330) *100
R = 11%

3. If the simple interest on a sum of money for 2 years at 5% per annum is Rs. 50, what is the compound interest on the same at the same rate and for the same time?
1. Rs. 51.25
2. Rs. 52
3. Rs. 54.25
4. Rs. 60
5. None of these

Explanation :-

S.I.= (PRT)/100
= (50100)/(52) = Rs.500
Amoun500(1+5/100)^2 = 500 * (21/20) ∗ (21/20=Rs. 551.25
C.I.551.25 − 500 = Rs. 51.25

4. 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?
1.8
2.10
3.12
4.Cannot be determined
5.None of these