The bankers discount and the true discount of a sum at 15% per annum simple interest for the same time are Rs.120 and Rs.60 respectively. What is the sum and the time? Choices
A) Sum = Rs.160 and Time = 6.6 years
B) Sum = Rs.120 and Time = 6.6 years
C) Sum = Rs.140 and Time = 6.6 years
D) Sum = Rs.200 and Time = 6 years
E) None of these
Explanation :   BD = Rs.120   TD = Rs.60   R = 15%   F = BD ×TD/(BD – TD)=120×60/(120–60)=120×60/60=Rs. 120   Sum = Rs.120 and Time = 6.6 yearsD = Simple Interest on the face value of the bill for unexpired time =FTR/100   ⇒120 = (120×T×15)/100   ⇒1200 = 12 × T × 15 ⇒100 = 15 × T   ⇒ T = 100/15 = 6.6 years Answer : Option Sum = Rs.120 and Time = 6.6 years
<result>B</result>
The bankers discount and the true discount of a sum at 15% per annum simple interest for the same time are Rs.120 and Rs.60 respectively. What is the sum and the time?