1. At an annual simple interest rate of 6%, the interest for 5 months is \(\cfrac{x}{10}\) rupees. What will the principal be?

(a) ₹ 2x (b) ₹ 4x (c) ₹ 10x (d) ₹ 20x

2. At an annual simple interest rate of \(x\%\), the interest on 120 rupees for 10 months will be _____ rupees.

3. At an annual rate of 10%, the difference between the simple interest and compound interest on ₹100 for 1 year is ₹1.

4. 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?

5. 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

6. 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

7. A bank provides an annual simple interest rate of 5%. At the beginning of the year, Mr. Dip deposited 15,000 rupees. Three months later, he withdrew 3,000 rupees, and three months after withdrawing the amount, he deposited 4,000 rupees again. At the end of the year, how much money will Mr. Dip receive from the bank, including interest?

8. Determine the principal amount for which the monthly interest will be 10 rupees at an annual simple interest rate of 5%.

9. If interest is compounded every 6 months, find the difference between compound interest and simple interest for ₹10,000 at an annual rate of 10% after one year.

(a) ₹ 50 (b) ₹ 25 (c) ₹ 75 (d) ₹ 0

10. The simple interest on ₹\(b\) for \(c\) months at an annual rate of \(a\%\).

(a) \(\cfrac{abc}{1200}\) (b) \(\cfrac{abc}{100}\) (c) \(\cfrac{abc}{200}\) (d) \(\cfrac{abc}{120}\)

11. At an annual interest rate of 4%, the difference between the simple interest and compound interest on a principal amount for 2 years is 40 rupees. Determine the principal amount.

12. 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?

13. 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?

14. 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.

15. 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.

16. At an annual interest rate of \( a\% \), if the interest for \( a \) years on a principal is \( b \) rupees, then the amount of the principal is—

(a) \(\cfrac{100a}{b}\)rupees (b) \(\cfrac{100a}{b^2}\) rupees (c) \(\cfrac{100b}{a}\)rupees (d) \(\cfrac{100b}{a^2}\)rupees

17. At an annual simple interest rate of \(X\%\), the interest on \(Y\) taka for \(Z\) months will be.

(a) \(\cfrac{XYZ}{1200}\) rupees (b) \(\cfrac{XYZ}{100}\) rupees (c) \(\cfrac{XYZ}{200}\) rupees (d) 0\(\cfrac{XYZ}{120}\)rupees

18. At an annual simple interest rate of 10%, if the interest for 5 years is x rupees, then the principal amount:

(a) ₹ 2x (b) ₹ 4x (c) ₹ 10x (d) ₹ 20x

19. 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

20. At an annual simple interest rate of \(x\%\), if the interest on a principal amount for \(x\) years is \(x\) rupees, what is the principal amount?

(a) \(x\) rupees (b) \(100x\) rupees (c) \(\cfrac{100}{x}\) rupees (d) \(\cfrac{100}{x^2}\) rupees

21. 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

22. 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

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. Uday Babu lent a certain amount of money to one person at an annual simple interest rate of 4% for 4 years, and twice that amount to another person at an annual simple interest rate of 10% for the same duration. He received ₹960 more interest from the second person than from the first. Find the total amount of money Uday Babu lent.

25. 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.

26. Calculate the amount of money for which the monthly interest will be 1 rupee at an annual simple interest rate of 5%.

27. Bimal Babu lent a certain amount of money to one person at an annual simple interest rate of 8% for 4 years, and twice that amount to another person at an annual simple interest rate of 10% for the same duration. Bimal Babu received ₹960 more interest from the second person than from the first. Find the total amount of money Bimal Babu lent.

28. 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?

29. 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.

30. At what annual rate of interest will the simple interest on ₹900 for 4 years be equal to the simple interest on ₹720 for 6 years at 5% per annum?