When difference between compound and simple interest for three years is Rs. 124 at 10% interest per annum, the principal is Rs. ______

Correct option is A

Given:

Difference between compound interest and simple interest for 3 years = ₹124

Rate of interest per annum = 10%

Time period = 3 years

Formula Used:

Difference between CI and SI for 3 years = $$P × (\frac{R}{100})^2 × \frac{(300 + R)}{100}$$​​

Solution:

$$124= P × (\frac{10}{100})^2 × (\frac{310}{100}) \\\ \\124= P × \frac{100}{10000} × (\frac{310}{100}) \\\ \\P= \text{Rs. 4000}$$