The banker’s discount on Rs. 1600 at 15% per annum is the same as true discount on Rs. 1680 for the same time and at the same rate. The time is
Answer: B
S.I. on Rs. 1600 = T.D. on Rs. 1680.
=> Rs. 1600 is the P.W. of Rs. 1680,
=> Rs. 80 is S.I. on Rs. 1600 at 15%.
=> 80 = 1600*T*15/100
=> 80 = 16*T*15
=> 5 = T*15
=> T = 1/3 year = 12/3 months
= 4 months