The present worth of a sum due after a certain time is $Rs. 1024$ and the banker's gain is $Rs. 36$. The true 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 $Rs.\, 7500$?

$A$ man bought a watch for $10 \%$ discount. If he had bought it for $20 \%$ discount,he would have saved $Rs.\, 125$ more. The marked price of the watch is (in $Rs.$):

The price of a chair is $Rs.\, 500$. It has been sold at two successive discounts of $10\%$ each. What is its selling price? (in $Rs.$)

Ticket for an adult is $Rs. 1500$ and that of a child is $Rs. 800$. One child goes free with two adults. If a group has $25$ adults and $12$ children,what is the discount the group gets? (in $\%$)

If $Rs. 21$ is the true discount on $Rs. 371$ for a certain time,what is the true discount on the same amount for double that time,the rate being the same in both the cases? (in $Rs.$)