The banker's gain of a certain sum due $2$ $years$ hence at $12 \frac{1}{2} \%$ per annum is $Rs.\,36$. The present worth is (in $Rs.$)

The marked price of an article is $Rs. 650$ and a customer pays $Rs. 585$ for it. What is the discount percentage (in $\%$)?

The holder of a bill for $Rs. 17850$ nominally due on $May 21, 1991$ received $Rs. 357$ less than the amount of the bill by having it discounted at $5 \%$. When was it discounted?

$Rs. 21$ is the true discount on $Rs. 371$ for a certain time at a certain rate of interest. If the rate of interest is kept the same,the true discount on the same sum for double that time will be (in $Rs.$)

The banker's gain on a sum due $2$ years hence at $10 \%$ p.a. is $Rs. 120$. The banker's discount is (in $Rs.$)

$A$ shopkeeper marks up his wares by $60 \%$ and offers a $10 \%$ discount. What will be the selling price (in $Rs.$) if the cost price is $Rs.\, 7500$?