Anand deposited a certain amount in a bank at 5% p.a simple interest. In how many years will this amount double itself?

Correct option is B

Given:
Interest rate = 5% per annum (simple interest)
The principal amount doubles.

Formula Used:

​$$A = P + \frac{P \cdot R \cdot T}{100}$$​
Where:

A is the final amount (which is double the principal),
P is the principal amount (the initial amount of money)
R is the rate of interest per period (as a percentage)
T is the time the money is invested or borrowed for, in years
Solution:

Let the principle = P and Time = T

Since the amount doubles, A = 2P

Then,

​$$2P = P + \frac{P \times 5 \times T}{100}$$

​$$P = \frac{P \times 5 \times T}{100}$$

$$1 = \frac{5 \times T}{100}$$

$$T = \frac{100}{5}$$

T = 20 years

Thus, the correct answer is (c).