The bankerâ€™s discount on Rs. 1600 at 10% per annum is the same as true discount on Rs. 1680 for the same time and at the same rate. The time is :
Choose the most appropriate option: A) 2 months B) 4 months C) 6 months D) 7 months E) None
Sol.   S.I. on Rs. 1600 = R.D. on Rs. 1680.   âˆ´ Rs. 1600 is the P.W. of Rs. 1680, i.e., Rs. 80 is S.I. on Rs. 1600 at 10%.   âˆ´ Time = [100 * 80 / 1600 * 10] year = 1/2 year = 6 months.   Answer 6 months
<result>C</result>
The bankerâ€™s discount on Rs. 1600 at 10% per annum is the same as true discount on Rs. 1680 for the same time and at the same rate. The time is :