If the selling price of an article is $\frac{4}{3}$ of its cost price,the profit percentage in the transaction is: (in $\%$)

The cash difference between the selling price of an article at a profit of $4 \%$ and $6 \%$ is $Rs. 3$. The ratio of the $2$ selling prices is?

$A$ 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 $8 \%$.

Tarun bought a $TV$ with $20 \%$ discount on the labelled price. Had he bought it with $25 \%$ discount,he would have saved $₹ 500$. At what price did he buy the $TV$?

$A$ merchant buys $4000 \, kg$ of wheat,one-fifth of which he sells at a gain of $5 \%$,one-fourth at a gain of $10 \%$,one-half at a gain of $12 \%$,and the remainder at a gain of $16 \%$. If he had sold the whole at a gain of $11 \%$,he would have made $Rs. 72.80$ more. What was the cost price of the crop per $kg$? (in $Rs.$)

If on selling $12$ notebooks,a seller makes a profit equal to the selling price of $4$ notebooks,what is his percent profit?