### Exercise 6.1

Q1. I have ₹ 5000 in my hand. I deposited that money in a bank at the rate of 8.5% compound interest per amount for two years. Let us write by calculating how much money I shall get at the end of 3 years.

Q2. Let us calculate the amount of ₹ 5000 at the rate of 8% compound interest per annum for 3 years.

Q3. Goutam babu borrowed ₹ 2000 at the rate of 6% compound interest per annum for 2 years. Let us write by calculating how much compound interest at the end of 2 years he will pay.

Q.4 Let us write by calculating the amount on ₹ 30000 at the rate of 9% compound interest per annum for 3 years.

Q.5 Let us write by calculating the amount on ₹ 80000 for 2 ½ years at the rate of 5% compound interest per annum.

Q.6 Chanda devi borrowed some money for 2 years in the compound interest at the rate of 8% per annum. Let us calculate if the compound interest is ₹ 2496, then how much money she had lended.

Q.7 Let us write by calculating the principal which becomes ₹ 2648 after getting 10% compound interest per annum for 3 years.

Q.8 Rahaman chacha deposited some money in a cooperative bank at the rate of 9% compound interest and the received amount ₹ 29702.50 after 2 years. Let us calculate how much money Rahaman chacha had deposited in cooperative bank.

Q.9 Let u write by calculating what sum of money at the rate of 8% compound interest per annum for 3 years will amount to ₹ 31492.80.

Q.10 Let us calculate the difference between the compound interest and simple interest on ₹ 12000 for 2 years., at 7.5% interest per annum.

Q.11 Let us write by calculating the difference between compound interest and simple interest on ₹ 10,000 for 3 years, at 5% per annum.

Q.12 Let us write by calculating the sum of money, if the difference between compound interest and simple interest for 3 years at the rate of 9% interest per annum is ₹ 129.60.

Q.13 Let us write by calculating the sum of money, if the difference between compound interest and simple interest tor 3 years becomes ₹930 at rate of 10% interest per annum.

Q.14 If the rates of compound interest for the first and the second year are 7% and 8% respectively, let us write by calculating compound interest on ₹ 6000 for two years.

Q.15 If the rate of compound interest for the first and second year are 5% and 6% respectively, let us calculate the compound interest on ₹ 5000 for 2 years.

Q16. If the simple interest of a certain sum of money for 1 year is ₹ 50 and compound interest for 2 years is ₹ 102, let us write by calculating the sum of money and the rate of interest.

Q.17 If simple interest and compound interest of a certain year of money for two years are ₹ 8400 and ₹ 8652, then let us write by calculating the area of money and the rate of interest.

Q.18 Let us calculate compound interest on ₹ 6000 for 1 year at the rate of 8% compound interest per annum compounded at the interval of 6 months.

Q.19 Let us write by calculating compound interest on ₹ 6250 at the rate of 10% compound interest per annum compounded at the interval of 3 months.

Q20.Let us write by calculating at what rate of interest per annum will ₹ 6000 amount to ₹ 69984 in 2 years.

Q.21 Let us calculate in how many years will ₹ 40000 amount in ₹ 46656 at the rate of 8% compound interest per annum.

Q22. Let us write by calculating at what rate of compound interest per annum, the amount on ₹10,000 for 2 years is ₹ 12100.

Q23. Let us calculate in how many years will ₹ 50000 amount in ₹60500 at the rate of 10% compound interest per annum.

Q24. Let us write by calculating in how many years will ₹ 30000 amount to ₹ 399300 at the rate of 10% compound interest per annum.

Q25. Let u calculate the compound interest and amount on ₹ 1600 for 1 ½ years at the rate of 10% compound interest per annum compounded of the interval of 6 months**.**

### Exercise 6.2

Q1. At present the population of the village of; Saharanpur is 10000; if the population Is being increased at the rate of 3% every year, let us write by calculating in population after 2 years.

Q2. Rate of increase in population of a state Is 2% in a year. The present population is 80000000; let us calculate the population of the state after 3 years.

Q3. The price of a machine in a leather factory depreciates at the rate of 10% every year. If the present price of the machine be ₹ 100000, let us calculate what will be the price of that machine after 3 years.

Q4. As a result of Sarba Siksha Abhiyan, the students leaving the school before completion, the student are readmitted, so the students un a year is increased by 5% in comparison to its previous year. If the member of such readmitted students in a distinct be 3528 in the present year. Let us write by calculating, the member of students readmitted 2 years before in this manner.

Q5. Through the publicity of road-safety programme, the street accident in Purulia district are decreased by 10% in comparison to its previous year. If the number of street accident in this year be 8748, let us write by calculating, the number of street accident 3 years before in the district.

Q6. A cooperative society of fisherman implemented such as improved plan for the production of fishes that the production in a year will be increased 10% in comparison to its previous year. In the present year if the cooperative society can produce 400 quintals of fishes, let us write by calculating, what will be the production of fishes after 3 years.

Q7. The height of tree increases at the rate of 20% every year. If the present height of tree is 28.8 meter, let us calculate the height of tree 2 years before.

Q8. Three years before from today a family had planned to reduce the expenditure of electric bill by 5% in comparison to its previous year. 3 years before, that family had to spend ₹ 4000 in a year for electric bill. Let us write by calculating how much amount will be family have to spent to pay the electric bill in the present year.

Q9. Weight of Savan babu is 80 kg. in order to reduces his weight, he started regular morning walk. He decided to reduce his weight every year by 10%. Let us write by calculating, his weight after 3 years.

Q10. At present the sum of the number of students in all M.S.K in a districts 3993. If the number of students increased in a year was 10% of its previous year, let us calculate the sum of the number of students 3 years before in all the M.S.K in the district.

Q11. As the farmers are becoming more alert of the harmful effects of applying only the chemical fertilizers and insecticides in agricultural lands, the number of farmers using fertilizers and insecticides in village of Rasulpur decreases by 20% in a year in comparison to its previous year. Three years before, the number of such farmers was 3000, let us calculate the number of such farmers in that village now.

Q12. The price of a machine of a factory is ₹ 180000. The price of that machine decreases by 10% in each year. Let us calculate its price after 3 years.

Q13. For the families having no electricity in their homes, a Panchayat samity of villages Bakultala accepted a plan to offer electric connection. 1200 in this village have no electric connection in their houses. In comparison to its previous year, it is possible to arrange electricity every year for 75% of the families having no electricity, let us write by calculating the number of families without electricity after 2 years.

Q14. As a result of continuous publicity on harmful reaction in the use of cold drinks filled bottles, the number of users of cold drinks decreased by 25% every year in comparison to us previous year. 3 years before number of users cold drink in a town was 80000. Let us write by calculating, the number of users of cold drink in the present year.

Q15. As a result publicity on smoking, the number of smoker is decreased by 6 ¼ every year in comparison to its previous year. If the number of smokers at present in a city is 33750, let us write by calculating, the number of smoker in that city 3 years before.