Ramesh deposited Rs 15600 in a fixed deposit at the rate of 10% per annum simple, interest. After every second year, he adds his interest earnings to the principal. The interest at the end of fourth year is

Options

A. Rs 1716
B. Rs 1560
C. Rs 3432
D. Rs 6864

Answer

To solve the problem step by step, we will calculate the simple interest earned by Ramesh over four years, considering that he adds the interest earned to the principal every two years.

### Step 1: Calculate the interest for the first two years.
- **Principal (P)** = Rs 15600
- **Rate (R)** = 10% per annum
- **Time (T)** = 2 years

Using the formula for Simple Interest (SI):
\[ SI = \frac{P \times R \times T}{100} \]
Substituting the values:
\[ SI = \frac{15600 \times 10 \times 2}{100} \]
\[ SI = \frac{156000}{100} = 1560 \]

### Step 2: Add the interest to the principal after two years.
- New Principal after 2 years = Original Principal + Interest
\[ New Principal = 15600 + 1560 = 17160 \]

### Step 3: Calculate the interest for the next two years using the new principal.
- **New Principal (P)** = Rs 17160
- **Rate (R)** = 10% per annum
- **Time (T)** = 2 years

Using the Simple Interest formula again:
\[ SI = \frac{17160 \times 10 \times 2}{100} \]
\[ SI = \frac{171600}{100} = 1716 \]

### Step 4: Calculate the total interest earned at the end of four years.
- Total Interest = Interest from the first two years + Interest from the next two years
\[ Total Interest = 1560 + 1716 = 3276 \]

### Final Answer:
The interest at the end of four years is Rs 3276.

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