Find the compound interest at the rate of 5% per annum for 3 years on that principal which in 3 years at the rate of 5% per annum given Rs 1200 as simple interest.

Explanation

To solve the problem, we first need to determine the principal amount (P) that gives a simple interest of Rs 1200 over 3 years at a rate of 5% per annum. Then, we will use this principal to calculate the compound interest for the same duration and rate.

### Step 1: Calculate the Principal Amount (P)

The formula for Simple Interest (SI) is:

\[
SI = \frac{P \times R \times T}{100}
...