A man invested Rs. 9600 to a post office scheme at 12.5% interest per annum at simple interest. But for a certain reason, he withdraws the whole money after 9 months. What total interest did he get at the time of withdraw?

Options

A. 652
B. 756
C. 900
D. 936

Answer

To find the total interest earned by the man who invested Rs. 9600 at a simple interest rate of 12.5% per annum for 9 months, we can follow these steps:

### Step 1: Identify the formula for Simple Interest
The formula for calculating Simple Interest (SI) is:
\[ \text{SI} = \frac{P \times R \times T}{100} \]
where:
- \( P \) = Principal amount (initial investment)
- \( R \) = Rate of interest per annum
- \( T \) = Time in years

### Step 2: Convert the time from months to years
Since the time given is in months, we need to convert it to years.
- Given time = 9 months
- To convert months to years, we divide by 12:
\[ T = \frac{9}{12} = \frac{3}{4} \text{ years} = 0.75 \text{ years} \]

### Step 3: Substitute the values into the formula
Now, we can substitute the values into the formula:
- \( P = 9600 \)
- \( R = 12.5 \)
- \( T = 0.75 \)

Substituting these values:
\[ \text{SI} = \frac{9600 \times 12.5 \times 0.75}{100} \]

### Step 4: Calculate the interest
Now, we perform the calculations step by step:
1. Calculate \( 9600 \times 12.5 = 120000 \)
2. Now multiply by \( 0.75 \):
\[ 120000 \times 0.75 = 90000 \]
3. Finally, divide by 100:
\[ \text{SI} = \frac{90000}{100} = 900 \]

### Conclusion
The total interest earned by the man at the time of withdrawal is **Rs. 900**.