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

A man buys an article for $10 \%$ less than its value and sells it for $10 \%$ more than its value. His gain or loss percent is

A shopkeeper sells notebooks at the rate of $Rs.\,457$ each and earns a commission of $4 \% .$ He also sells pencil boxes at the rate of $Rs.\,80$ each and earns a commission of $20 \% .$ How much amount of commission will he earn in two weeks if he sells $10$ notebooks and $6$ pencil boxes a day?

A trader sells his table at a profit of $15 \%$ and the chair at a loss of $7 \frac{1}{2} \%,$ but on the whole he gains $Rs.\, 50 .$ If he sells the table at a loss of $7 \frac{1}{2} \%,$ and chair at a profit of $15 \%,$ then he neither gains nor loses. Find the cost price of the table

A pen was sold for a certain sum and there was a loss of $20 \% .$ Had it been sold for $Rs.\, 12$ more, there would have been a gain of $30 \% .$ What would be the profit if the pen was sold for $Rs.\, 4.80$ more than what it was sold for? (in $\%$)

The cost price of an article is $64 \%$ of the marked price. The gain percentage after allowing a discount of $12 \%$ on the marked price is........$\%$