1. 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

2. If the simple interest for \(n\) years at an annual rate of \(r\%\) is \(\frac{pnr}{25}\) rupees, then the principal amount will be _____ rupees.

3. If the total simple interest on a principal amount at an annual rate of \(x\%\) for \(y\) years is \(\frac{pyx}{25}\) rupees, then the principal amount will be:

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

4. If the difference between the compound interest and the simple interest on a certain sum of money for 2 years at an annual interest rate of 9% is ₹129.60, then find the principal amount.

5. 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?

6. If the simple interest on a certain amount at an annual interest rate of 8% for 2 years is ₹850, then what will be the compound interest for the same period?

(a) ₹ 1684 (b) ₹984 (c) ₹ 884 (d) none of the above

7. A certain principal doubles in 20 years at a fixed simple interest rate. At the same rate of simple interest, the principal will become four times in—?

(a) 40 years (b) 60 years (c) 80 years (d) none of the above

8. 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?

9. A certain principal doubles in 20 years at a given rate of simple interest. At the same rate of simple interest, that principal will become triple in —

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

10. At an annual interest rate of 9%, if the difference between the compound interest and simple interest on a certain amount for 2 years is ₹129.60, then calculate and write that principal amount.

11. If the difference between the compound interest and simple interest on a certain amount for 3 years at an annual interest rate of 10% is ₹930, then calculate and write that principal amount.

12. 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

13. If the total amount becomes 966 rupees at an annual simple interest rate of 3% in 5 years, the principal amount will be -

(a) 480 rupees (b) 408 rupees (c) 404 rupees (d) 840 rupees

14. If the annual simple interest on a principal is \(\cfrac{1}{9}\) of it, then what will be the accumulated amount in 4 years if the total sum becomes 1326 rupees?

(a) ₹ 1080 (b) ₹ 1120 (c) ₹ 918 (d) ₹ 750

15. If the time period and the annual simple interest rate are equal, then at what annual interest rate will the interest amount be \(\cfrac{1}{25}\) of the principal?

(a) 25% (b) 10% (c) 2% (d) 2.5%

16. 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

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

18. 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.

19. If the ratio of principal to amount after 1 year is 4:9, then the annual simple interest rate will be 5%.

20. 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\(\cfrac{2}{3}\%\)

21. 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.

22. For a fixed amount of money, at a fixed annual rate of interest, the compound interest and simple interest will be equal in -- years.

23. 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.

24. 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?

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

26. If a certain amount becomes ₹1357 in 15 years at an annual simple interest rate of 7%, what is the interest amount?

(a) ₹ 695 (b) ₹ 771 (c) ₹ 717 (d) none of the above

27. If the ratio of a certain principal amount to its compound amount after a certain period is 15:21 and the annual simple interest rate is 5%, then the duration of time is –

(a) 4 years (b) 2 years (c) 8 years (d) 10 years

28. 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

29. Anil Babu wants to allocate ₹56,000 between his two sons, aged 13 and 15, such that when they turn 18, the simple interest earned at an annual rate of 10% is equal to their respective principal amounts. Determine the amount allocated to each son in the will.

30. In how many years will the amounts of simple interest and compound interest be equal for the same principal at the same annual interest rate?

(a) 3 years (b) 2 years (c) 1 years (d) \(\frac{1}{2}\)