If $11$ mangoes are bought for $Rs. 10$ and sold at $10$ for $Rs. 11$,what is the gain or loss percentage (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 $Rs.$)

By selling $100$ oranges,a vendor gains the selling price of $20$ oranges. His gain percent is

$A$ man sold two cows at $Rs. 1995$ each. On one he lost $10\%$ and on the other he gained $10\%$. What is his gain or loss percent (in $\%$)?

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 $\%$)

Profit earned by selling an article for $Rs. 1630$ is the same as the loss incurred by selling the article for $Rs. 1320$. What is the $CP$ in $Rs$?