1. At an annual simple interest rate of \(x\%\), if the interest on a principal amount for \(x\) years is \(x\) rupees, what is the principal amount?

(a) \(x\) rupees (b) \(100x\) rupees (c) \(\cfrac{100}{x}\) rupees (d) \(\cfrac{100}{x^2}\) rupees

2. 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.

3. If \(\frac{1}{6}\) of a principal amount is earned as annual simple interest, what will be the percentage rate of interest?

(a) 10\(\cfrac{2}{3}\%\) (b) 16\(\cfrac{2}{3}\%\) (c) 12% (d) 9\(\cfrac{2}{3}\%\)

4. If a principal amount doubles in \(x\) years, the annual simple interest rate is -.

5. If a principal amount doubles in x years, what is the annual simple interest rate?

6. If a principal amount doubles in 10 years, what is the annual simple interest rate?

(a) 5% (b) 10% (c) 15% (d) 20%

7. If a principal amount doubles in 10 years, what is the annual simple interest rate?

(a) 5% (b) 10% (c) 15% (d) 20%

8. If a principal amount doubles in 10 years, what is the annual simple interest rate?

(a) 5% (b) 10% (c) 15% (d) 20%

9. Here’s the English translation of your question: At a certain fixed rate of simple interest, if a principal amount becomes double in \(x\) years and triple in \(y\) years, then what is the ratio \(x:y\)?

(a) 2:3 (b) 1:2 (c) 3:2 (d) 2:1

10. At an annual simple interest rate of 5%, a person deposits some money in the bank. After 5 years, how much total amount will he receive, if the principal is 12,500 rupees less than the total amount (principal + interest?

11. If a principal amount doubles in 10 years, what will be the annual simple interest rate ?

(a) 5% (b) 10% (c) 15% (d) 20%

12. At an annual simple interest rate of \(x\%\), if the interest on a principal in \(x\) years is \(x\) rupees, then the amount of the principal is –

(a) \(x\) rupees (b) \(100x\) rupees (c) \(\cfrac{100}{x}\) rupees (d) \(\cfrac{100}{x^2}\) rupees

13. If the interest on a principal amount becomes \(\cfrac{3}{8}\) of the principal in 5 years, what is the rate of interest?

(a) 6% (b) 7.5% (c) 8% (d) 10.5%

14. Under the same simple interest rate, a principal amount grows to 7000 rupees in 5 years and 8200 rupees in 8 years. What is the rate of interest?

(a) 4% (b) 6% (c) 8% (d) 10%

15. At an annual simple interest rate of 12%, if the ratio of principal to interest after \(x\) years is 25:24, what is the value of \(x\)?

(a) 8 (b) 10 (c) 12 (d) 5

16. If a principal amount doubles in 10 years, then the annual simple interest rate is—?

(a) 5% (b) 10% (c) 15% (d) 20%

17. If the ratio of principal to amount after 1 year is 20 : 21, what is the annual rate of simple interest (in percentage)?

18. A farmer deposits ₹100 at the post office on the first day of every month. If the annual rate of simple interest is 5%, what will be the total amount (principal + interest) he receives at the end of the year?

19. If after one year the ratio of the principal to the amount (principal + interest) is 10 : 12, what is the annual rate of simple interest (in percentage)?

20. If the ratio of the principal to the amount after annual compound interest is 25 : 27, then what is the rate of interest?

(a) 6% (b) 8% (c) 10% (d) 12%

21. Mr. Amal bequeaths ₹56,000 in his will for his two sons aged 13 and 15 in such a way that, when they each turn 18, the simple interest earned at an annual rate of 10% will be equal to the principal for each. What will be the allocated amount for each son in the will?

22. If the difference between the compound interest and simple interest on a certain principal for 2 years at an annual rate of 5% is ₹25, then what is the amount of the principal?

23. At an annual simple interest rate of \(\cfrac{a}{5}\)%, if the interest on ₹\(a^2\) for \(\cfrac{a}{3}\) years equals the principal amount, then what is the value of \(\cfrac{a^3}{60}\)?

24. If the interest on a certain amount of money at an annual rate of 5% for 8 years is ₹246 more than the interest at an annual rate of 7% for 4 years, what is the principal amount?

(a) ₹ 5020 (b) ₹ 2000 (c) ₹ 2050 (d) ₹ 2005

25. If the simple interest on a certain principal at an annual interest rate of 18% for 2 years is ₹800, what will be the compound interest?

(a) ₹ 672 (b) ₹ 872 (c) ₹ 560 (d) ₹ 730

26. Bimal Kaku deposited 56,000 INR in a bank for his two sons, aged 13 and 15 years, in such a way that when they turn 18, the simple interest earned at an annual rate of 10% on each deposit equals the respective principal amount. Determine how much he deposited in each son's name.

27. If the difference between the compound interest and simple interest on a certain sum for 3 years at an annual rate of 10% is 930 rupees, then what is the principal amount?

28. If a principal amount doubles in 10 years, the annual simple interest rate is...?

(a) 8% (b) 10% (c) 6% (d) 5%

29. What would be the annual simple interest rate (percentage) if the interest for 4 years on a certain amount is \(\cfrac{8}{25}\) of the principal?

30. Due to the decrease in the annual simple interest rate from 4% to 3\(\frac{3}{4}\)%, a person's annual income decreases by 60 rupees. What is the principal amount of that person?