Question

In a time span of 5 years, the sum amounts to double itself. If the sum is ₹3,000, then what is the rate of interest?

• A. 10%
• B. 20%
• C. 5%
• D. 15%

Answer 1

The correct option is B 20%

Given,
Principle = ₹3,000;
Given that the amount doubles itself
Amount = 2 $\times$ 3000 = ₹6,000
$\therefore$ Interest earned = Amount - Principle
= 6000 - 3000 = ₹3,000
Time = 5 years

S.I = $\frac{P\times R\times T}{100}$
$\Rightarrow$ 3,000 = $\frac{3,000\times R\times 5}{100}$
$\Rightarrow$ 3,000$\times$100 = $3,000\times R\times 5$
$\Rightarrow$ R = $\frac{3,000\times 100}{3,000\times 5}$

$\Rightarrow$ R = 20%