The banker’s discount on a sum of money for 3 years is Rs. 1116. The true discount on the same sum for 4 years is Rs. 1200. What is the rate percent?
Answer: D
BD for 3 years = Rs. 1116
BD for 4 years = 1116*4/3 = Rs.1488
TD for 4 year = Rs.1200
F = (BD*TD)/(BD -TD) = (1488*1200)/(1488 -1200) = 124*1200/24 = 124*100/2 = 62*100 = Rs.6200
=> Rs.1488 is the simple interest on Rs. 6200 for 4 years
=> 1488 = (6200*4*R)/100
=> R=(1488*100)/(6200*4) = 372*100/6200 = 372/62 = 6%