The simple interest on a sum of money is Rs. 50 What is the sum ?
(i) the interest rate is `10%` p.a.
(ii) The sum earned simple interest in 10 years.

Answer

To solve the question, we need to find the principal sum (P) using the formula for simple interest (SI). The formula for simple interest is:

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

Where:
- \(SI\) = Simple Interest
- \(P\) = Principal amount (the sum we want to find)
- \(R\) = Rate of interest (in percentage)
- \(T\) = Time (in years)

Given:
- \(SI = 50\) (the simple interest earned)
- \(R = 10\%\) (the interest rate)
- \(T = 10\) years (the time period)

### Step 1: Substitute the known values into the formula

We can substitute the values we have into the simple interest formula:

\[ 50 = \frac{P \times 10 \times 10}{100} \]

### Step 2: Simplify the equation

Now, simplify the equation:

\[ 50 = \frac{100P}{100} \]

This simplifies to:

\[ 50 = P \]

### Step 3: Solve for P

From the equation above, we can see that:

\[ P = 50 \]

Thus, the sum (the principal amount) is Rs. 50.

### Final Answer

The sum of money is Rs. 50.

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