Ramesh marks his goods $30 \%$ above cost price. If he sells the item for $Rs. 910$ after allowing a discount of $15 \%$,find his cost price (in $Rs.$).

$A$ retailer gets a discount of $40 \%$ on the printed price of an article. The retailer sells it at the printed price. His gain percent is

At $20 \%$ discount,the selling price of an article is $Rs. 2400$. What is the selling price (in $Rs.$) if the discount is $32.5 \%$?

$A$ retailer marks up his goods by $150 \%$ and offers a $40 \%$ discount. What will be the selling price (in $Rs.$) if the cost price is $Rs.\, 800$?

The true discount on a bill of $Rs. 2550$ due after $3$ months is $Rs. 50$. Find the banker's discount (in $Rs.$).

$Rs.\, 20$ is the true discount on $Rs.\, 210$ due after a certain time. What will be the true discount on the same sum due after half of the former time,the rate of interest being the same? (in $Rs.$)