1. At an annual interest rate of 5%, for how many years will the interest on 300 rupees amount to 120 rupees?

(a) 4 (b) 8 (c) 12 (d) 12\(\frac{1}{2}\)

2. At an annual simple interest rate of 8%, in how many years will 5000 rupees grow to 7400 rupees?

(a) 3 years (b) 4 years (c) 5 years (d) 6 years

3. 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

4. Rahmat Chacha borrowed ₹240000 from a bank at an annual simple interest rate of 12% to build a house. One year after borrowing, he started renting out the house for ₹5200 per month. Calculate and determine after how many years from borrowing he will be able to repay the bank loan along with interest using the rental income.

5. 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?

6. If the annual interest rate and time period are equal, in how many years will the interest on 144 rupees become 25 rupees?

(a) 4 years (b) \(4\cfrac{1}{6}\) years (c) 6 years (d) \(6\cfrac{1}{4}\) years

7. If the annual rate of interest and the time in years are equal, then in how many years will the interest on ₹324 amount to ₹16?

(a) \(2\cfrac{2}{9}\) (b) \(2\cfrac{1}{9}\) (c) \(2\cfrac{4}{9}\) (d) \(2\cfrac{5}{9}\)

8. Sure! The Bengali sentence: **"কোনো মূলধন বার্ষিক 6 \(\frac{1}{4}\)% সরল সুদের হারে কত বছরে দ্বিগুণ হবে তা লিখি ।"** translates to English as: **"Write how many years it will take for a principal to double at an annual simple interest rate of 6 \(\frac{1}{4}\)%."** Would you like help solving this too?

9. At an annual compound interest rate of 20%, in how many years will ₹1000 amount to ₹1440?

10. A person borrows ₹2,40,000 at an annual simple interest rate of 12% to build a house. One year after taking the loan, they start renting out the house for ₹5,200 per month. After how many years from taking the loan will the rental income be enough to repay the entire loan along with the accrued interest?

11. At an annual compound interest rate of 4%, in how many years will a principal amount of ₹40,000 accumulate to ₹46,656?

12. Write down the calculation to determine in how many years a sum of money will double at an annual simple interest rate of 6%.

13. Write down the calculation to determine in how many years a simple interest of ₹168 will be earned on a principal of ₹600 at an annual rate of 8%.

14. Write how many years it will take for a principal to double at an annual simple interest rate of 6 \(\frac{1}{4}\)%.

15. Let us determine in how many years ₹40000 will amount to ₹46656 at an annual compound interest rate of 8%.

16. Determine in how many years ₹50000 will amount to ₹60500 at an annual compound interest rate of 10%.

17. Calculate and write in how many years ₹300000 will amount to ₹399300 at an annual compound interest rate of 10%.

18. At an annual interest rate of 4%, for how much money will the difference between the simple interest and the compound interest for 2 years be 80 rupees? Let’s calculate and write it down.

19. At an annual compound interest rate of 10%, in how many years will ₹4000 amount to ₹5324? Let’s calculate and write it down.

20. Determine how many years it will take for ₹105 interest to accumulate on ₹500 at an annual compound interest rate of 10%.

21. 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

22. 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

23. At an annual simple interest rate of 10%, how much money will become 14,000 rupees in 4 years?

(a) ₹ 12500 (b) ₹ 12000 (c) ₹ 12600 (d) ₹ 10000

24. At an annual simple interest rate of 8%, how much interest will make the principal amount grow to \(\cfrac{7}{5}\) times its original value?

(a) 4 years (b) 5 years (c) 6 years (d) 7 years

25. What will be the total amount of 450 rupees after 3 years at an annual simple interest rate of 4%?

(a) ₹ 135 (b) ₹ 180 (c) ₹ 504 (d) ₹ 600

26. At an interest rate of 4%, in how many years will 350 rupees earn 70 rupees in interest?

(a) 5 years (b) 10 years (c) 8 years (d) 7 years

27. At an annual simple interest rate of 6%, in how many years will the interest on ₹\(x\) amount become ₹\(\frac{9x}{25}\)? Find the value of the time.

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

28. If a sum of money becomes 4 times its original amount in *n* years at a fixed annual compound interest rate, then in how many years will it become 4 times?

29. If a certain amount of money doubles in 4 years at a fixed annual compound interest rate, in how many years will it become four times?

30. If a sum of money doubles in \(n\) years at a fixed annual compound interest rate, then in how many years will it become 4 times?