The marked price of a bed is $Rs. 2400$. The shopkeeper gives successive discounts of $10 \%$ and $X \%$ to the customer. If the customer pays $Rs. 1836$ for the bed,then find the value of $X$ in $\%$.

If the cost price of $12$ pens is equal to the selling price of $8$ pens,find the gain percent.

$APD$ printed $3000$ copies of 'Career Power' at a cost of $Rs. 240000$. It gave $500$ copies free to different philanthropic institutions. It allowed a discount of $25\%$ on the published price and gave one copy free for every $25$ copies bought at a time. It was able to sell all the copies in this manner. If the published price is $Rs. 325$,then what is its overall gain or loss percentage in the whole transaction?

$A$ shopkeeper cheats to the extent of $10 \%$ while buying as well as selling by using false weights. His total gain percentage is:

Harkesh bought a certain quantity of tomato at the rate of $Rs. 1500$ per quintal. $10 \%$ of the tomato was spoiled. At what price in $Rs.$ per quintal should he sell the remaining to gain $20 \%$ of his outlay?

$A$ dishonest dealer defrauds to the extent of $x \%$ in buying as well as selling his goods by using faulty weight. What will be the gain per cent on his outlay?