If the selling price of $40$ articles is equal to the cost price of $50$ articles,the loss or gain percent is

$A$ dealer buys a table listed at $Rs. 600$ and gets successive discounts of $10\%$ and $20\%$. What is his profit or loss percent if he sells it at $Rs. 540$?

$A$ reduction of $21\%$ in the price of an item enables a person to buy $3\, Kg$ more for $₹ 100$. The reduced price of the item per $Kg$ is (in $₹$):

Anil started a business with an investment of $Rs. 25,000$. After $3$ months,Vishal joined his business with a capital of $Rs. 30,000$. At the end of the year,they made a profit of $Rs. 19,000$. What will be Anil's share in the profit? (in $Rs.$)

$A$ person earns $15 \%$ on an investment but loses $10 \%$ on another investment. If the ratio of the two investments is $3:5$,what is the gain or loss percentage on the two investments taken together (in $\%$)?

$APD$ 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?