If the selling price of $50$ articles is equal to the cost price of $40$ articles,then the loss or gain percent is:

$A$ shopkeeper professes to sell his goods at cost price but uses a weight of $800 \text{ g}$ instead of a $1 \text{ kg}$ weight. His profit percentage is:

$A$ man bought some fruits at the rate of $16$ for $Rs. 24$ and sold them at the rate of $8$ for $Rs. 18$. What is the profit percent (in $\%$)?

$A$ tradesman marks his goods $30 \%$ more than the cost price. If he allows a discount of $6 \frac{1}{4} \%$ then his gain percent is

Two successive discounts of $4 \%$ on any item are equivalent to a single discount of $\%$

$A$ shopkeeper gains $17 \%$ after allowing a discount of $10 \%$ on the marked price of an article. Find his profit percent if the article is sold at the marked price allowing no discount. (in $\%$)