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

$A$ $TV$ set is being sold for $Rs. x$ in Chandigarh. $A$ dealer went to Delhi and bought the $TV$ at a $20\%$ discount (from the price of Chandigarh). He spent $Rs. 600$ on transport. Thus,he sold the set in Chandigarh for $Rs. x$,making a $14 \frac{2}{7}\%$ profit. What was $x$ in $Rs.?$

Kunal bought a suitcase with $15 \%$ discount on the labelled price. He sold the suitcase for $Rs. 2880$ with $20 \%$ profit on the labelled price. At what price did he buy the suitcase? (in $Rs.$)

$A$ 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 $26 \text{ kg}$ of rice at $Rs. 20$ per $\text{kg}$ with $30 \text{ kg}$ of rice of another variety at $Rs. 36$ per $\text{kg}$ and sells the mixture at $Rs. 30$ per $\text{kg}$. His profit percent is:

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: