1. A certain sum of money amounts to ₹944 in 3 years at simple interest. If the rate of interest is increased by 25%, the same sum amounts to ₹980 in the same time period. Find the principal amount and the original rate of interest.

2. Under the same rate of interest, the simple interest on ₹800 for 3 years and ₹1000 for 5 years together amounts to ₹592. What is the rate of interest?

(a) 6% (b) 8% (c) 7% (d) 9%

3. If the simple interest on ₹850 for 3 years and on ₹1250 for 4 years at the same rate amounts to ₹302 in total, then what will be the annual rate of interest?

(a) 3% (b) 5% (c) 7% (d) None of the above

4. Mr. Bimal deposited ₹5,600 in a bank at a simple interest rate of 10% for his 13-year-old son and 15-year-old daughter in such a way that when both turn 18 years old, they each receive the same amount including interest. How much money did he deposit separately for his son and daughter?

5. Some money amounts to 944 rupees in 3 years at simple interest. If the annual rate of interest increases by 25%, then the same money amounts to 980 rupees in the same time. Find the rate of interest and the principal.

6. Some money becomes 5 times its original amount in 5 years at simple interest. At the same rate of interest, the time required for that principal to become 17 times is:

(a) 17 years (b) 20 years (c) 18 years (d) 19 years

7. Uday Babu lent a certain amount of money to one person at an annual simple interest rate of 4% for 4 years, and twice that amount to another person at an annual simple interest rate of 10% for the same duration. He received ₹960 more interest from the second person than from the first. Find the total amount of money Uday Babu lent.

8. Bimal Babu lent a certain amount of money to one person at an annual simple interest rate of 8% for 4 years, and twice that amount to another person at an annual simple interest rate of 10% for the same duration. Bimal Babu received ₹960 more interest from the second person than from the first. Find the total amount of money Bimal Babu lent.

9. ₹1200 is deposited for 4 years and ₹2000 for 3 years in a bank at the same rate of simple interest. If the total interest earned is ₹594, what is the annual rate of interest (percentage)?

10. ₹6300 is divided into two parts in such a way that the simple interest on the first part at an annual rate of 10% for 6 years is equal to the simple interest on the second part at an annual rate of 15% for 3 years. Find the amounts of the two parts.

(a) ₹ 2700,₹3600 (b) ₹ 3000,₹ 3300 (c) ₹ 4000,₹ 2300 (d) ₹ 5000,₹ 1300

11. Bimal Babu deposited ₹1,87,500 in a bank at an annual simple interest rate of 5% for his 12-year-old son and 14-year-old daughter in such a way that when both turn 18, they receive equal amounts, including interest. Determine how much he deposited separately for his son and daughter.

12. What is the difference between the simple interest and compound interest on ₹1250 for 2 years at a rate of 4%?

(a) ₹ 8 (b) ₹ 4 (c) ₹ 3 (d) ₹ 2

13. A farmer deposited some money in the village post office. After 4 years, he found that the total amount including interest had become ₹434. He calculated that the interest he received was \(\frac{6}{25}\) of his principal amount. Find how much money he had originally deposited and what annual rate of simple interest the post office gave.

14. The simple interest and compound interest on a certain principal for 2 years are ₹4,000 and ₹4,100 respectively. Find the principal and the rate of interest.

15. The simple interest for 2 years and the compound interest for 1 year (with annual compounding) on the same principal at the same rate are ₹800 and ₹820 respectively. Find the principal and the rate of interest.

16. Raju lent ₹400 to Ajay for 2 years and ₹100 to Manoj for 4 years. He received a total of ₹60 as simple interest from both. What is the annual rate of simple interest?

17. If a certain principal amount amounts to ₹1248 in 7 years and ₹1056 in 4 years at the same annual rate of simple interest, find the principal and the annual rate of simple interest.

18. If the simple interest and compound interest on a certain principal for 2 years are ₹8400 and ₹8652 respectively, then determine the principal and the annual rate of interest.

19. Arpita lent ₹400 to Rakhi for 5 years and ₹900 to Minu for 3 years, receiving a total interest of ₹94 from both. The annual interest rate is-

(a) 2% (b) 4% (c) 6% (d) 8%

20. If the interest on ₹1250 at a rate of 4% for 3 years is equal to the interest on ₹375 at a rate of 5% for \(x\) years, find the value of \(x\).

(a) 5 (b) 8 (c) 7 (d) 6

21. If the simple interest on a certain principal for 2 years at an annual rate of 15% is ₹160, find the compound interest.

(a) ₹ 205 (b) ₹ 172 (c) ₹ 200 (d) none of the above

22. Determine the principal and the annual simple interest rate if a sum of money amounts to ₹7100 in 7 years and ₹6200 in 4 years at the same annual rate of simple interest.

23. Rahmat Chacha borrowed ₹240000 from a bank at an annual simple interest rate of 12% to build a house. One year after borrowing, he started renting out the house for ₹5200 per month. Calculate and determine after how many years from borrowing he will be able to repay the bank loan along with interest using the rental income.

24. Bimal Kaku deposited ₹187,500 in a bank at an annual simple interest rate of 5% for his 12-year-old son and 14-year-old daughter, in such a way that when both children turn 18, they each receive the same amount (principal plus interest). Let us calculate how much money he deposited for his son and daughter individually.

25. Ramen Babu deposited a total of ₹370,000 across three banks. The annual simple interest rates for these three banks are 40%, 5%, and 6%, respectively. After one year, the amount of interest he earns from each bank is the same. Let us calculate how much money he deposited in each of the three banks.

26. If the simple interest on a certain principal for 1 year is ₹50 and the compound interest for 2 years is ₹102, then calculate and write the amount of the principal and the annual rate of interest.

27. If the simple interest and compound interest on a certain principal for 2 years are ₹8400 and ₹8652 respectively, then calculate and write the amount of the principal and the annual rate of interest.

28. If the compound amount on ₹60000 for 2 years is ₹69984, then calculate and write the annual rate of interest.

29. At an annual simple interest rate of \(r\%\), if the total interest on a principal for \(n\) years is \(\cfrac{pnr}{25}\) rupees, then the amount of the principal is –

(a) \(2p\) rupees (b) \(4p\) rupees (c) \(\cfrac{p}{2}\) rupees (d) \(\cfrac{p}{4}\) rupees

30. At an annual simple interest rate of 5%, how many years will it take for the interest on ₹6000 to become ₹1500?

(a) 3 years (b) 30 years (c) 5 years (d) 15 years