If $11$ Mango are bought for $Rs.\, 10$ and sold at $10$ for $Rs.\, 11 .$ What was Gain or Loss $\% ?$

Rita buys an article for $Rs.$ $9600.$ She sold it at $12 \%$ loss and get some money and from that money she again buys an article and this time she got $12 \%$ profit. What was profit or loss she got form this transaction in $Rs.$?

$'A ^{\prime}$ sells a good to $'B ^{\prime}$ at a profit of $10 \%$ and $B$ sells it to $'C ^{\prime}$ at a profit of $20 \% .$ Find out the resultant profit. (in $Rs.$)

The cost price of $6$ pens is equal to the selling price of $4$ pens. Find the profit percent.

An $Ox$ and a carriage together cost $Rs.$ $8000$ The ox is sold at profit of $10 \%$ and carriage is sold at loss of $10 \% .$ If total profit made is $2.5 \%$ then what is the cost price of the $ox$? (in $Rs.$)

A merchant purchases a wrist watch for $Rs.\,450$ and fixes its list price in such a way that after allowing a discount of $10 \%,$ he earns a profit of $20 \%$. Then the list price (in rupees) of the wrist watch is