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

$A$ loss of $19 \%$ gets converted into a profit of $17 \%$ when the selling price is increased by $Rs. 162$. The cost price of the article is (in $Rs.$)

Paras Health Care made $3000$ strips of vitamin tablets at a cost of $Rs. 4800$. The company gave away $1000$ strips of tablets to doctors as free samples. $A$ discount of $25\%$ is given on the printed price. Find the ratio of profit in $Rs.$ if the price is raised from $Rs. 3.25$ to $Rs. 4.25$ per strip and if at the latter price,samples to doctors were done away with.

Peter purchased a machine for $Rs. 80000$ and spent $Rs. 5000$ on repairs and $Rs. 1000$ on transport,then sold it with a $25\%$ profit. At what price did he sell the machine? (in $Rs$)

Hundred oranges are bought at the rate of $Rs. 350$ and sold at the rate of $Rs. 48$ per dozen. The percentage of profit or loss is:

$A$ fruit seller sells mangoes at the rate of $Rs. 9$ per $kg$ and thereby loses $20\%$. At what price per $kg$ should he have sold them to make a profit of $5\%$? (in $Rs.$)