Explain the Rate of Interest Calculation

Step 1: Understand the problem and formula

The problem states that a sum of money doubles itself on simple interest in 10 years.
The formula for simple interest is:
SI = (P × R × T) / 100,
where P is the principal amount, R is the rate of interest, and T is the time in years.

Step 2: Set up the equation

If the sum of money doubles, then the Amount (A) becomes 2P.
Since A = P + SI, we get: 2P = P + SI.
Therefore, SI = P.

Step 3: Substitute and solve for R

Substitute SI = P and T = 10 into the formula:
P = (P × R × 10) / 100

Now solving for R:
1 = (R × 10) / 100 100 = 10R R = 100 / 10 R = 10%

Answer:

The correct answer is (A) 10%.