In what time will a sum of money double itself at the rate of 12.5% per annum simple interest?

Correct option is B

Given:

Rate of interest (R) = 12.5% per annum

The sum of money doubles itself, so the amount (A) is twice the principal (P), i.e., A = 2P

Formula Used:

Simple Interest formula

S.I = $$\frac{P \times R \times T}{100}$$​​

Amount = P + $$\frac{P \times R \times T}{100}$$​​

Where:

A = Total amount

P = Principal

R = Rate of interest

T = Time in years

Solution:

Applying the formula;

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

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

​$$1 = \frac{R \times T}{100}$$​​

​$$T = \frac{100}{R}$$​​

​$$T = \frac{100}{12.5} = 8 \, \text{years}$$​​

The time required to double the sum of money at the rate of 12.5% per annum simple interest is 8 years.