1. 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.

2. If a certain principal amount yields a total of ₹7,400 in simple interest after 4 years at an annual rate, and another total of ₹6,200 in simple interest after 4 years, calculate the principal and the annual rate of simple interest.

3. 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.

4. 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.

5. 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.

6. At the same rate of simple interest, a certain principal amounts to ₹1056 in 4 years and ₹1248 in 7 years. Find the rate of interest and the principal.

7. If a certain principal earns ₹560 in 3 years and ₹600 in 5 years at the same annual simple interest rate, find the amount of the principal and the annual rate of simple interest.

8. 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.

9. 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.

10. 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.

11. 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.

12. 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.

13. At an annual interest rate of 10%, compounded semi-annually, the difference between the compound interest and simple interest over 2 years is ₹124.05. Find the principal amount.

14. Bimalkaku deposited ₹187,500 in a bank at an annual 5% simple interest for his 12-year-old son and 14-year-old daughter, in such a way that when both of them turn 18, they will each receive the same amount of money (principal + interest). How much money did he deposit for his son and daughter respectively?

15. A bank gives simple interest at an annual rate of 5%. A person deposited ₹15,000 at the beginning of the year. After 3 months, he withdrew ₹3,000, and 3 months after the withdrawal, he deposited ₹8,000 again. Calculate the total amount (principal + interest) he will receive at the end of the year.

16. What should be the annual rate of simple interest (in percent) so that the interest on a sum of money for 10 years becomes \(\frac{2}{5}\) of the total amount (principal + interest)?

17. If ₹800 is deposited in a bank at an annual simple interest rate of 10%, and the total amount received (principal + interest) is ₹1200, then calculate and write for how long the money was deposited in the bank.

18. Determine the annual simple interest rate (percentage) at which the interest on a certain amount over 10 years becomes \(\frac{2}{5}\) of the total amount (principal + interest).

19. If a certain principal earns ₹560 in 3 years and ₹600 in 5 years at the same annual simple interest rate, determine the principal amount and the annual percentage rate of simple interest.

20. My aunt wants to will ₹56,000 between her two sons, aged 13 and 15, in such a way that by the time each turns 18, the total amount (principal + interest) received by both sons is equal. The interest is calculated at an annual simple interest rate of 10%. Determine how much should be allotted to each son in the will.

21. 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.

22. If the simple interest and compound interest on a certain principal for 2 years are 840 rupees and 869.40 rupees respectively, then let’s calculate and write down the principal amount and the annual rate of interest.

23. At an annual simple interest rate of x%, the interest and total amount (principal + interest) for ₹12y over 10 months is —

24. A certain amount of money amounts to ₹700 in 4 years at simple annual interest, and during this time the interest is 40% of the principal. What is the amount of the principal?

(a) ₹ 500 (b) ₹ 400 (c) ₹ 600 (d) ₹ 300

25. 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

26. At an annual percentage rate of interest, the simple interest and compound interest on a principal amount are equal after —— years.

27. If the ratio of a principal amount and its amount after 5 years is 5 : 6, then find the annual simple interest rate.

28. A borrowed ₹960 from B at an annual simple interest rate of 6%, with the condition that the loan will be repaid over the next 4 yearly installments. In the first 3 installments, A will pay only one-fourth of the principal each year. In the final (4th) installment, A will pay the remaining principal along with the total interest accrued over the 4 years. Find the total amount A will pay at the end of the 4th year.

29. ₹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)?

30. 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.