$A$ shopkeeper sells $20$ pencils for the same amount of money as he paid for $25$ pencils. What is his gain percent?

$A$ shopkeeper mixes $26 \, kg$ of wheat which costs $Rs. 20$ per $kg$ with $30 \, kg$ of wheat which costs $Rs. 36$ per $kg$ and sells the mixture at $Rs. 30$ per $kg$. Find the profit percent. (in $\%$)

$A$ rice trader buys $8$ quintals of rice for $Rs. 3,600$. $10\%$ of the rice is lost in transportation. At what rate should he sell the remaining rice to earn a $15\%$ profit in $Rs.$ per quintal?

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 $Rs.$?

$A$ $TV$ 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 $Rs.?$

$A$ single discount,equivalent to a successive discount of $40 \%$ and $30 \%$ is in $\%$?