1. 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

2. 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

3. A principal amount doubles in 20 years at a certain simple interest rate. At the same rate, in how many years will the principal become three times?

4. If a principal amount doubles in 20 years at a certain simple interest rate, then at the same rate, the principal will triple in – ?

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

5. If a principal amount doubles in 20 years at a certain simple interest rate, then in how many years will it triple at the same simple interest rate?

6. 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

7. If a principal doubles in 5 years at a certain simple interest rate, then in how many years will it quadruple at the same rate?

(a) 12 (b) 14 (c) 15 (d) 16

8. If 1200 rupees grows to 1584 rupees in 4 years with simple interest, then how much principal amount will grow to 2800 rupees in 5 years?

(a) ₹ 2000 (b) ₹ 1800 (c) ₹ 2500 (d) ₹ 2100

9. 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

10. If a principal amount doubles in 8 years at an annual compound interest rate of \(r\%\), then in how many years will it become four times?

11. If a sum of money doubles in \(n\) years at an annual compound interest rate, then it will become four times in –

(a) \(2n\) years (b) \(\cfrac{n}{2}\) years (c) \(3n\) years (d) \(\cfrac{n}{3}\) years

12. If a certain principal amount becomes 5 times its original value in 20 years due to interest, then the rate of interest is –

(a) 20% (b) 25% (c) 15% (d) 10%

13. 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

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. If a certain principal amount triples in 15 years at simple interest, then the annual rate of simple interest will be —

(a) \(13\frac{1}{3}\%\) (b) \(12\frac{1}{3}\%\) (c) \(11\frac{1}{3}\%\) (d) \(10\frac{1}{3}\%\)

16. 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.

17. Which one will be less: the simple interest for 2 years or the compound interest with annual compounding for 2 years, on a fixed principal, if the rate of interest is the same?

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 a principal becomes five times through simple interest in 10 years, then in how many years will it become nine times the original amount including interest?

(a) 18 (b) 20 (c) 25 (d) 30

20. If a principal amount yields a total of ₹7,100 (principal + simple interest) in 7 years and ₹6,200 in 4 years at the same annual rate of simple interest, find the principal and the annual rate of simple interest.

21. If ₹27,500 doubles in 6 years at compound interest, then in how many years will it become four times?

(a) 16 (b) 15 (c) 12 (d) 10

22. At the same interest rate, the simple interest on a certain amount for 3 years is ₹1200, and the compound interest for 2 years is ₹832. Determine the interest rate and the principal amount.

23. If a principal amount doubles in 10 years, the annual simple interest rate will be 20%.

24. At the same annual percentage interest rate, the simple interest and compound interest on a principal amount become equal in _____ years (interest period: 1 year).

25. If a certain amount of money doubles in \(n\) years at a fixed annual compound interest rate, then in how many years will it become four times?

26. 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

27. If a certain amount of money triples in 20 years, then at the same simple interest rate, in how many years will it double?

28. If a principal amount doubles in 4 years at a compound interest rate of \(r\%\), then it will become 4 times in ______ years.

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

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

30. If \(\cfrac{1}{20}\) of a principal is the annual interest, the simple interest rate will be:

(a) 4% (b) 5% (c) 10% (d) 8%