Question

A man invests certain amount at 6% per annum simple interest and another amount at 7% per annum simple interest. His income from the interest after 2 years was Rs. 348. The ratio of first amount to second is 4:5. Find the total amount invested.

• A. Rs. 2600
• B. Rs. 2900
• C. Rs. 2700
• D. none of the above

Answer 1

The Correct Option is D

To solve the given problem, let's use the information provided: the man invests amounts in the ratio of 4:5, with parts of this investment earning 6% and 7% simple interest, respectively. We need to determine the total amount invested. Let's define variables to represent the amounts invested:

• Let the amount invested at 6% be \(4x\). 
• Let the amount invested at 7% be \(5x\).

From this, the total amount invested is:

\(4x + 5x = 9x\)

Let's calculate the interest from each of these investments. The simple interest formula is \( \text{Interest} = \frac{\text{Principal} \times \text{Rate} \times \text{Time}}{100} \).

• The interest on \(4x\) at 6% for 2 years is: \( \frac{4x \times 6 \times 2}{100} = 0.48x \).
• The interest on \(5x\) at 7% for 2 years is: \( \frac{5x \times 7 \times 2}{100} = 0.7x \).

The total interest from both parts is:

\(0.48x + 0.7x = 1.18x\)

According to the problem, the total interest is Rs. 348:

\(1.18x = 348\)

Solving for \(x\), we divide both sides by 1.18:

\(x = \frac{348}{1.18} \approx 295.76\)

Thus, the total amount invested is:

\(9x \approx 9 \times 295.76 = 2661.84\)

Since the problem options do not include this amount, the correct answer is 'none of the above'.