Correct Answer - Option 1 : 6400
Given:
Amount in 2 years = Rs.291600
Amount in 3 years = Rs.314928
Formula:
Let P = Principal, R = rate of interest and N = time period
Compound interest = P(1 + R/100)n - P
Amount = P(1 + R/100)n
Simple interest = PNR/100
Calculation:
⇒ 291600 = P(1 + R/100)2
⇒ 314928 = P(1 + R/100)3
⇒ 1.08 = (1 + R/100)
⇒ R = 8%
Rate of interest is 8% per annum.
Then,
Simple interest = 40000 × 8 × 2/100 = Rs.6400
∴ simple interest on Rs.40000 at the same rate for 2 years is Rs.6400.