Vimal invested a certain amount at simple interest. The total amount sum to Rs. 14760 and Rs. 16140 after 2 years and 3 years respectively. What is the rate of interest at which Vimal invested the amount?
C
Correct answer
Explanation
Let P be principal, R be rate. Amount after 2 years = P(1 + 2R/100) = 14760. Amount after 3 years = P(1 + 3R/100) = 16140. Subtracting: P(R/100) = 16140 - 14760 = 1380. So PR/100 = 1380. From first equation: P + 2PR/100 = 14760. P + 2(1380) = 14760. P = 14760 - 2760 = 12000. Then: 12000R/100 = 1380. 120R = 1380. R = 1380/120 = 11.5%. Option C is correct.