On selling an article for $Rs. 500$,the loss incurred is $20 \%$. To make a profit of $20 \%$,the article must be sold at what price in $Rs.$?

$A$ vendor started selling vegetables at $Rs. 10$ per $kg$,but could not find buyers at this rate. So,he reduced the price to $Rs. 8.10$ per $kg$,but uses a faulty weight of $900\, g$ for $1\, kg$. Find the percent change in the actual price or loss. (in $\%$)

$A$ shopkeeper sells a badminton racket,whose marked price is $Rs. 30$,at a discount of $15\%$ and gives a shuttlecock costing $Rs. 1.50$ free with each racket. Even then,he makes a profit of $20\%$. His cost price per racket is (in $Rs$):

$A$ person sells a colour $TV$ at $10\%$ below the cost price. Had he received $Rs. 1494$ more,he would have made a profit of $12 \frac{1}{2}\%$. What was the cost price of the colour $TV$ (in $Rs.$)?

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

Profit earned by selling an article for $Rs. 1630$ is the same as the loss incurred by selling the article for $Rs. 1320$. What is the $CP$ in $Rs$?