1. If the annual simple interest rate increases from 4% to 5%, causing a person's income to rise by ₹1000, then the person's principal amount is _____.

(a) ₹ 4000 (b) ₹ 5000 (c) ₹ 10000 (d) ₹ 50000

2. 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?

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

4. If the annual simple interest rate decreases from 5.5% to 4.5%, and a person's yearly interest income is reduced by ₹250 as a result, what is the principal amount?

5. The annual simple interest rate decreases from \( 4\% \) to \( 3\frac{3}{4}\% \), causing a person's yearly income to reduce by 60 rupees. Find the principal amount of that person.

6. A person's annual income decreases by ₹60 when the rate of interest drops from 4% to \(3\frac{3}{4}\)% (i.e., 3.75%). Find the principal amount.

7. Due to the annual simple interest rate decreasing from \(4\%\) to \(3\frac{3}{4}\%\), a person's annual income decreases by ₹60. Find that person's principal amount.

8. Due to a decrease in the annual simple interest rate from \(4\%\) to \(3\frac{3}{4}\%\), a person's annual income is reduced by ₹600. Find that person's principal (capital).

9. Due to a decrease in the annual simple interest rate from 4% to 3\(\cfrac{3}{4}\)%, Mr. Amal's annual income is reduced by ₹60. Find Mr. Amal's principal.

10. Due to the annual simple interest rate decreasing from 4% to 3\(\frac{3}{4}\)%, Amal Babu's annual income reduces by ₹60. Determine Amal Babu's principal amount.

11. Some money amounts to 944 rupees in 3 years at simple interest. If the annual rate of interest increases by 25%, then the same money amounts to 980 rupees in the same time. Find the rate of interest and the principal.

12. Mr. Jayanta deposits ₹1,000 on the first day of every month in a monthly scheme. If the annual simple interest rate is 5%, then how much total amount (principal + interest) will he receive at the end of the year?

13. 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

14. Due to the annual simple interest rate decreasing from 6% to 5\(\frac{1}{2}\)%, a person's annual income decreased by 75 rupees. How much money had they deposited in the bank?

15. Due to the annual simple interest rate decreasing from 4% to 3 \(\frac{3}{4}\)% (i.e. 3.75%), Mr. Amal's annual income decreases by ₹60. Calculate Mr. Amal's principal (capital).

16. At an annual simple interest rate of \(r\%\), if the total interest on a principal for \(n\) years is \(\cfrac{pnr}{25}\) rupees, then the amount of the principal is –

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

17. A certain sum of money amounts to ₹944 in 3 years at simple interest. If the rate of interest is increased by 25%, the same sum amounts to ₹980 in the same time period. Find the principal amount and the original rate of interest.

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

20. Ramen Babu deposits a total of ₹3,70,000 in three banks. The annual simple interest rates of the three banks are 4%, 5%, and 6% respectively. After one year, the total interest earned from each bank is the same. How much money did he deposit in each bank?

21. If the ratio of a principal amount to its annual amount with interest is 20:25, then the annual interest rate will be 4%.

22. 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

23. If the ratio of principal to amount after 1 year is 4:9, then the annual simple interest rate is 12.5%.

24. If the ratio of a certain principal amount to the interest accrued over a given period is 20:7, and the annual simple interest rate is 6%, then the duration of time is –

(a) 6 years (b) 5\(\cfrac{5}{6}\) years (c) 6\(\cfrac{5}{7}\) years (d) none of the above

25. Rambabu divided his total money between two banks in such a way that he received equal interest from both banks after one year. The annual interest rates of the two banks are 4% and 5%, respectively. The amount of money deposited in the second bank is — of the amount deposited in the first bank.

(a) \(\frac{1}{2}\) part (b) \(\frac{1}{3}\) part (c) \(\frac{1}{6}\) part (d) twice

26. At an annual simple interest rate of \(x\%\), if the total interest on a principal amount for \(y\) years is \(\cfrac{xyz}{25}\) rupees, then the principal amount is –

(a) ₹ 2z (b) ₹ 4z (c) \(\cfrac{z}{2}\) (d) \(\cfrac{z}{4}\)

27. If ₹800 is deposited in a bank at an annual simple interest rate of 10%, and the total amount received (principal + interest) is ₹1200, then calculate and write for how long the money was deposited in the bank.

28. At an annual simple interest rate of \(r\%\), if the total interest in \(n\) years is ₹\(\cfrac{pnr}{25}\), then the principal amount is —

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

29. My aunt wants to will ₹56,000 between her two sons, aged 13 and 15, in such a way that by the time each turns 18, the total amount (principal + interest) received by both sons is equal. The interest is calculated at an annual simple interest rate of 10%. Determine how much should be allotted to each son in the will.

30. Ramen Babu deposited a total of ₹370,000 across three banks. The annual simple interest rates for these three banks are 40%, 5%, and 6%, respectively. After one year, the amount of interest he earns from each bank is the same. Let us calculate how much money he deposited in each of the three banks.