$A$ trader sells rice at a profit of $5 \%$ and uses a weight which is $25 \%$ less. Find the total percentage gain.

In a certain store,the profit is $320 \%$ of the cost. If the cost increases by $25 \%$ but the selling price remains constant,approximately what percentage of the selling price is the profit?

$A$ sold a pen to $B$ at a profit of $20\%,$ $B$ sold the same pen to $C$ for $Rs.\,75$ thereby making a profit of $25 \% .$ Find the price at which $A$ bought the pen? (in $Rs.$)

$A$ man sells an article at $5 \%$ above its cost price. If he had bought it at $5 \%$ less than what he had paid for it and sold it at $Rs. 2$ less,he would have gained $10 \%$. The cost price of the article is (in $Rs.$)

$A$ trader marks his goods $40 \%$ above the cost price and allows a discount of $25 \%$. The profit he makes,is in $\%$:

If the cost price of $20$ articles is equal to the selling price of $15$ articles,find the profit percent?