Question

If a sum become four times in 15 years, then what will be the rate of simple interest per annum?
1. 21%
2. 19%
3. 25%
4. None of the above

Answer 1

Correct Answer - Option 4 : None of the above

Given:

Amount = 4 × sum

Number of years = 15 years

Formula used:

SI = (P × R × T)/100

SI → Simple interest, P → Principal, R → Rate, T → Time

Calculations:

Let the sum be 'x'

Amount = 4x

Simple interest = 4x - x = 3x

Hence, 3x = (x × 15 × R)/100

⇒ 1 = R/20

⇒ R = 20%

∴ The rate of interest per annum is 20%