An amount becomes 3 times of itself in 20 years. What is the rate of simple interest per annum?
Answer & explanation
Correct answer: option 2
Let Principal = 1
Amount = 3 × P = 3
So, Interest = Amount - Principal = 3 - 1 = 2
T = 20 years
SI = \(\frac{P\;R\;T}{100}\)
$2=\frac{1×R×20}{100}$ ⇒ R = 10%.