The marked price of a watch was $Rs. 720$. $A$ man bought the same for $Rs. 550.80$ after getting two successive discounts,the first being $10\%$. What was the second discount rate? (in $\%$)

An article is marked for sale at $Rs. 504$. The shopkeeper gives a discount of $5\%$ on the marked price and still earns a profit of $20\%$. What is the cost price of the article? (in $Rs.$)

$A$ fruit-seller buys some oranges and by selling $40 \%$ of them he realizes the cost price of all the oranges. As the oranges begin to grow over-ripe,he reduces the price and sells $80 \%$ of the remaining oranges at half the previous rate of profit. The rest of the oranges being rotten are thrown away. The overall percentage of profit is (in $\%$)

$A$ fan is listed at $Rs. 1500$ and a discount of $20 \%$ is offered on the list price. What additional discount must be offered to the customer to bring the net price to $Rs. 1104$? (in $\%$)

By selling a book for $Rs. 360$,$20\%$ profit was earned. What is the $CP$ of the book in $Rs.$?

When a producer allows $36 \%$ concession on the retail price of his product,he earns a profit of $8.8 \% .$ What would be his profit percent if the concession is reduced by $24 \% ?$