Revision - ix

Compound Intrest 

1) On what sum of money, the difference between the simple interest and compound intrest in 2 years at 5% per annum is Rs 15?     

2) A certain sum of money is invested at 5% intrest, compounded annually, for 3 years. If the intrest computes to Rs 2522, determine the principal.   

3) In how many years will a sum of Rs 800 at 10% per annum compounded semi-annually become Rs 926.10?      

4) Ram invests Rs 5600 at 8% p.a. compound intrest for 5  year. Find:

a) The intrest for the first year.

b) The amount at the end of the first year.

c) The intrest for the second year, correct to the nearest rupee.

d) The intrest for 2 years.

e) The amount at the end of 2 years.   

5) Find the compound intrest on Rs 27000 for 3 years at 4% per annum.   

6) The difference between the C.I and S. I on a certain sum for 2 years at 10% is Rs 50. Find the sum.     

7) The C. I and S. I on a sum of money for 2 years is Rs 210 and Rs 200. If the rate of interest is the same, find the sum and the rate.     

8) A sum of money put out at compound intrest amounts to Rs 800 in 3 years and to Rs 840 in 4 years. Find the rate of interest.     

9) A sum of money put out at C. I amounts to Rs 6720 in 2 years and to Rs 7560 in 3 years. Find the rate of interest.  

10) Minal lenda Rs 6000 at CI for 2 years. The rate of interest she charged for the 1st and 2nd year were 6% and 8% respectively. Find the amount she received after 2 years.   

11) The present population of a town is 75000. The population increases by 10% in the 1st year and decreases by 10% in the 2nd year. Find the population after 2 years. 

12) The cost of a machine depriciates by 10% every year. If its present value is Rs 900, what will be its value after three years?