# Find Rate of Interest if Money doubles itself in 10 years at Simple Interest

A sum of money doubles itself in 10 years at simple interest. What is the rate of interest?

- 10%
- 25%
- 14%
- 12%

**Answer: (1) 10**

**Explanation:-
**Let the money be Rs.X and rate = R%.

A sum of money doubles itself in 10 years at simple interest.

Then, Simple Interest = 2 X – X = X

Formula-

Simple Interest = Principal x Time x Rate/100

Then, X = X x 10 x R/100

1 = R/10

R = 10%

Then, the rate of interest is 10%.

Hence, the answer is (1) 10%.