What is the banker’s discount, if the true discount on a bill of Rs. 840 is Rs.105?

Answer: Option C

Present Worth (P.W.) = 840 - 105 = Rs. 735
Therefore, S.I. on Rs. 735 = Rs. 105
S.I. on Rs. 8400
= $$\frac{105\times 840}{735}$$
= Rs. 120