Question

At what rate percent per annum will the simple interest on a sum of money be 2/5 of the principal in 10 years?
1. 4%
2. \(6^\frac{2}{3}\)%
3. 6%
4. \(5^\frac{2}{3}\)%

Answer 1

Correct Answer - Option 1 : 4%

Given:

S.I.= (2/5) of Principal

Time = 10 years

Formula used:

Amount = P + ( P × R × T)/100

Where P,R and T represents Principal, rate and time respectively.

Calculation:

S.I. = (P × R × T)/100

⇒ (2/5) of P = (P × R × 10)/100

⇒ (2/5) = (R × 10)/100

⇒ (2/5) = (R)/10

⇒ R = 4%

∴ Rate is 4% per annum.