UPSC CAPF Assistant Commandant Model Paper 1

Simple interest received by Sushma = PRT/100
P = principle = Rs. 24000,R = rate of interest = 15%,T = time = 1.5 years
Simple interest = (24000 × 15 × 1.5)/100 = Rs. 5400
Total amount received by Sushma after 1.5 years at 15% simple interest
= 24000 + 5400 = Rs. 29400
Total amount received by Sushma after 1.5 years at 20% CI = P × [1 + r/100] ‌N
P = principle = Rs. 24000, N = number of terms = 2 × 1.5 = 3, r = rate of interest = 20/2 = 10%
Amount = 24000 × [1 + 10/100] ‌3 = Rs. 31944
Required difference = 31944 - 29400 = Rs. 2544