There is a profit of $20 \%$ on the cost price of an article. The per cent of profit, when calculated on the selling price is.......$\%$

The marked price of an article is $Rs. 5000$. Due to a special festive offer,a certain percentage of discount is declared. Mr. $X$ availed this opportunity and bought the article at the reduced price. He then sold it at $Rs. 5000$ and thereby made a profit of $11 \frac{1}{9} \%$. The percentage of discount allowed was:

$A$ shopkeeper sold an article offering a discount of $5 \%$ and earned a profit of $23.5 \%$. What would have been the percentage of profit earned if no discount had been offered?

$A$ person sells $36$ apples per rupee and suffers a loss of $4 \%$. Find how many apples per rupee should be sold to have a gain of $8 \%$.

$A$ man sells an article at a loss of $5 \%$. If he had bought it at $20 \%$ more and sold it for $Rs. 115$ less,he would have made a loss of $40 \%$. Find the cost price of the article.

$A$ shopkeeper sold some articles at $Rs. 35$ per piece and gained $40 \%$. What would be the selling price of each article to earn $60 \%$ profit? (in $Rs.$)