$A$ shopkeeper sells goods at $10 \%$ loss on cost price,but uses $20 \%$ less weight. What is his profit or loss percentage?

$A$ person sells $36$ oranges for $₹ 1$ and makes a loss of $4 \%$. Find how many oranges per $₹ 1$ should be sold to have a gain of $8 \%$.

$A$ man purchased $120$ reams of paper at $Rs. 80$ per ream. He spent $Rs. 280$ on transportation,paid octroi at the rate of $40$ paise per ream,and paid $Rs. 72$ to a porter. In order to gain $8\%$ profit,he must sell each ream of paper for (in $Rs.$):

$A$ trader mixes three varieties of groundnuts costing $Rs. 50$,$Rs. 20$,and $Rs. 30$ per $kg$ in the ratio $2:4:3$ by weight and sells the mixture at $Rs. 33$ per $kg$. What is the percentage of profit he makes?

Aditya purchased a book with a $20 \%$ discount on the marked price. How much $Rs.$ did he pay if the marked price of the book was $Rs. 500$?

$A$ shopkeeper sells $25$ articles at $Rs. 45$ per article after giving a $10 \%$ discount and earns a $50 \%$ profit. If no discount is given,the profit percentage gained is......$\%$