The banker’s discount on Rs. 1850 due to certain time hence is Rs. 185. Find the true discount and the banker’s gain ?

Rs.16

Rs.12

Rs.15

Rs.18

Explanation:

Given that
B.G. = Rs. 185
Sum = Rs. 1850
Now, Sum = $\dfrac{B.G.∗T.D}{B.G.–T.D} $
= $\dfrac{B.G.∗T.D}{B.G}$
Therefore, $\dfrac{T.D}{B.G}$
= $\dfrac{sum}{B.D}$
= $\dfrac{1850}{185}$
= 10
Thus, if B.G. is Re. 1, T.D. = Rs. 10.
If B.D. is Rs. 185
T.D. = Rs.($\dfrac{10}{11} \times 185$)
= Rs. 169
B.G. = Rs. (185 – 169) = Rs. 16.