1. What should be the annual compound interest rate for a certain amount of money to become 1.96 times that amount in 2 years?

2. What should be the annual compound interest rate for ₹625 to grow to ₹784 in 2 years?

3. What should be the annual interest rate (percentage) for a principal amount to become three times its original value in 25 years?

4. 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)?

5. If the principal is \(p\) rupees and the annual compound interest rates for the first, second, and third years are \(r_1\%\), \(r_2\%\), and \(r_3\%\) respectively, then what will be the total compound amount after 3 years?

6. If the compound amount of ₹400 in 2 years becomes ₹441, find the annual compound interest rate (percentage).

7. If the principal amount of **₹400** becomes **₹441** in 2 years under compound interest, determine the annual percentage rate of compound interest.

8. If the total compound amount for ₹400 after 2 years is ₹441, what is the annual compound interest rate?

9. What should be the annual interest rate for a principal amount to double in 6 years?

(a) 12% (b) 12\(\cfrac{1}{2}\)% (c) 16% (d) 16\(\cfrac{2}{3}\)%

10. A man left ₹28,000 for his 13-year-old son and 15-year-old daughter with the instruction that, at the age of 18, the amount each receives — including simple interest at an annual rate of 10% — should be equal. Determine the amount allocated to each child.

11. At an annual interest rate of 4%, how much money should be invested so that the total amount becomes ₹3600 in 5 years?

12. What should be the annual simple interest rate (in percentage) so that the interest on a sum of money for 6 years becomes \(\frac{18}{25}\) of the principal?

13. At an annual interest rate of 10%, the ratio of simple interest to compound interest on ₹100 for 2 years will be –.

(a) 10:11 (b) 11:10 (c) 20:21 (d) 21:20

14. If a certain principal becomes 7 times in a fixed period at an annual interest rate of 6%, what should the annual interest rate be for it to become 10 times?

(a) 10% (b) 12% (c) 16% (d) 9%

15. What is the difference between the compound interest and simple interest on ₹1950 at an annual interest rate of 8% for 2 years?

(a) ₹ 18 (b) ₹ 12.48 (c) ₹ 48.12 (d) ₹ 24

16. At an annual interest rate of \(6\cfrac{2}{3}\%\), determine the time required for the amount to become \(1.5\) times the principal.

17. At an equal annual interest rate, determine the number of years required for the simple interest and compound interest on a given principal to become equal.

18. If interest is compounded every 6 months, then at an annual compound interest rate of 10%, what is the total compound amount and compound interest on 8000 rupees for \(1\frac{1}{2}\) years?

19. At an annual interest rate of 5%, what will be the difference between compound interest and simple interest for ₹20,000 over 2 years?

20. Write the calculation to determine the principal amount for which the compound interest for 3 years at an annual compound interest rate of 10% will be ₹2648.

21. A principal amount doubles in 20 years at a certain simple interest rate. At the same rate of simple interest, the time required for the principal to become three times will be:

(a) 30 Years (b) 35 Years (c) 40 Years (d) 45 Years

22. 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

23. 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

24. What should be the principal amount so that the compound amount becomes ₹169 in 2 years at a 4% interest rate?

(a) ₹ 156.25 (b) ₹160 (c) ₹150.50 (d) ₹ 154.75

25. What should be the annual rate of simple interest (in percentage) so that the interest earned in 4 years becomes \( \frac{2}{5} \) of the principal amount?

26. What should be the annual rate of simple interest (in percentage) so that the interest earned in 4 years becomes \(\frac{8}{25}\) of the principal amount?

27. Aminur borrowed ₹64,000 from a bank. If the bank's interest rate is 2.5 paise per rupee per year, then what will be the compound interest on that amount for 2 years?

28. If interest is compounded every 6 months, then at an annual compound interest rate of 10%, what will be the compound amount and compound interest on ₹8000 for 1½ years?

29. 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.

30. What should be the annual rate of simple interest so that the interest for 5 years becomes \(\frac{1}{4}\) of the principal?