Anil borrowed some money at simple interest. The rate of interest for the first 3 years was` 5%` for the next 2 years was` 8%` and for the next 4 years it was` 10%`. Beyond this it was` 12%` per annum. If he paid Rs. 8560, as interest for 12 years. How much money did he borrow ?

Options

A. Rs. 8000
B. Rs. 6000
C. Rs. 5000
D. Rs. 7000

Answer

To find out how much money Anil borrowed, we will use the formula for simple interest and the information provided in the question.

### Step-by-Step Solution:

1. **Identify the Interest Rates and Time Periods:**
- For the first 3 years, the interest rate is 5%.
- For the next 2 years (years 4 to 5), the interest rate is 8%.
- For the next 4 years (years 6 to 9), the interest rate is 10%.
- For the last 3 years (years 10 to 12), the interest rate is 12%.

2. **Calculate the Total Interest Contribution from Each Period:**
- For the first 3 years:
\[ \text{Interest} = P \times \frac{5}{100} \times 3 = 0.15P \]
- For the next 2 years:
\[ \text{Interest} = P \times \frac{8}{100} \times 2 = 0.16P \]
- For the next 4 years:
\[ \text{Interest} = P \times \frac{10}{100} \times 4 = 0.4P \]
- For the last 3 years:
\[ \text{Interest} = P \times \frac{12}{100} \times 3 = 0.36P \]

3. **Sum Up All the Interest Contributions:**
\[ \text{Total Interest} = 0.15P + 0.16P + 0.4P + 0.36P = 1.07P \]

4. **Set Up the Equation Using the Given Total Interest:**
- We know that the total interest paid over 12 years is Rs. 8560.
\[ 1.07P = 8560 \]

5. **Solve for P (Principal Amount):**
\[ P = \frac{8560}{1.07} \approx 8000 \]

### Conclusion:
Anil borrowed approximately Rs. 8000.