Simple Interest Quiz

The simple interest on a principal amount is Rs. 192 for a period of 2 years at the rate of 8% per annum. The principal amount is :

• ` 1,000

• ` 1,400

• ` 1,200

• ` 1,600

Answer explanation

To find the principal, use the formula for simple interest: SI = (P * R * T) / 100. Here, SI = 192, R = 8, and T = 2. Rearranging gives P = (SI * 100) / (R * T) = (192 * 100) / (8 * 2) = 1200. Thus, the principal amount is Rs. 1,200.

Ravi took a loan from a bank at the rate of 8% p.a. simple interest. After 5 years, he had to pay an interest of `6,400 for the period. Find the Principal amount borrowed by Ravi.

• ` 10,000

• ` 16,000

• ` 15,000

• ` 18,000

Answer explanation

To find the principal, use the formula for simple interest: Interest = Principal × Rate × Time. Here, 6400 = Principal × 0.08 × 5. Solving gives Principal = 6400 / (0.08 × 5) = 16000. Thus, the correct answer is `16,000.

A sum becomes `26,400 after 2 years at simple interest of 5% per annum. Find the sum.

• `29,040

• `2,640

• `2,400

• `24,000

Answer explanation

The formula for simple interest is A = P(1 + rt). Here, A = 26,400, r = 0.05, and t = 2. Rearranging gives P = A / (1 + rt) = 26,400 / (1 + 0.1) = 24,000. Thus, the sum is `24,000.

Manvi borrowed some money on simple interest, at the rate of 6% p.a. for the first three years, at the rate of 9% p.a. for the next five years and at the rate of 13% p.a. for the period beyond eight years. If the total interest paid by him at the end of eleven years is `8,160, how much money did he borrow?

• `11,000

• `10,000

• `8,000

• `12,000

Answer explanation

To find the principal, we calculate the interest for each period: 3 years at 6%, 5 years at 9%, and 3 years at 13%. The total interest of `8,160 corresponds to a principal of `8,000, confirming the correct choice.

A man invests money in three different schemes for 6 years, 10 years and 12 years, at 10%, 12% and 15% simple interest, respectively. If the completion of each scheme, he gets the same interest then the ratio of the respective investments is:

• 7 : 4 : 3

• 6 : 3 : 2

• 5 : 4 : 3

• 4 : 3 : 2

Answer explanation

Let investments be x, y, z. Interest from each scheme: 6x*10%, 10y*12%, 12z*15%. Setting them equal gives: 0.6x = 1.2y = 1.8z. Solving yields x:y:z = 6:3:2, confirming the correct ratio is 6:3:2.

If the annual rate of simple interest increases from 8% to 1 12 % 2, a person's yearly income from interest increases by `369 then what is the principal amount of his investment?

• `8,150

• `8,200

• `8,100

• `8,500

Answer explanation

The increase in interest is calculated as: Principal x (1.12% - 8%) = 369. Solving for Principal gives 8,200. Thus, the correct principal amount is `8,200.

Certain amount becomes `230 in 3 years at 5% simple interest per annum. Then the principal amount (`) is:

• 180

• 150

• 200

• 320

Answer explanation

To find the principal, use the formula: A = P + SI. Here, SI = (P * r * t) / 100. Given A = 230, r = 5%, and t = 3, we can set up the equation: 230 = P + (P * 5 * 3) / 100. Solving gives P = 200.

A man invested 1 2 of his capital at 5% rate of interest per annum, 1 3 of his capital at 8% per annum and the remaining at 10% rate of interest per annum. His total income from the three investments is `820.00 in a year. The total capital invested is

• ` 16000.00

• ` 6400.00

• ` 12000.00

• ` 8000.00

Answer explanation

Let the total capital be x. The investments are (1/2)x at 5%, (1/3)x at 8%, and (1/6)x at 10%. The total income equation is (0.05)(1/2)x + (0.08)(1/3)x + (0.10)(1/6)x = 820. Solving gives x = 12000. Thus, the total capital is `12000.00.

A sum of money of `2600.00 was lent out in two parts in such a way that the simple interest on the first part at 10% per annum for 5 years is the same as the interest of the second part at 9% per annum for 6 years. The part lent out at 10% is -

• `1250.00

• `1350.00

• `1450.00

• `1150.00

Answer explanation

Let the first part be x. Then, the second part is 2600 - x. The interest equations are: 0.1*x*5 = 0.09*(2600-x)*6. Solving gives x = 1350. Thus, the part lent out at 10% is `1350.00.

Balaji invested 1 7 of his total investment at 4%, 1 2 at 5% and the rest at 6% for 1 year. He received a total interest of `730. What was the total sum invested?

• `7,000

• `24,000

• `14,000

• `38,000

Answer explanation

Let total investment be x. Balaji invested (1/7)x at 4%, (1/2)x at 5%, and the rest at 6%. The interest equation is (1/7)x*0.04 + (1/2)x*0.05 + (5/14)x*0.06 = 730. Solving gives x = 14,000.