The selling price of a radio was $Rs. 255$ when $15 \%$ discount was allowed. Then the marked price of the radio was (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 $Rs.\, 7500$?

$Rs. 20$ is the true discount on $Rs. 260$ due after a certain time. What will be the true discount on the same amount due after half of the earlier time,the rate of interest being the same? (in $Rs.$)

$A$ shopkeeper allows a $20 \%$ discount on the marked price of his articles. Find the marked price of an article for which he charges $Rs. 740$. (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 price of an article is cut by $42 \%$. To restore it to its original value,the new price must be increased by (in $\%$):