$A$ man gains $20 \%$ by selling an article for a certain price. If he sells it at double the price,what will be the percentage of profit (in $\%$)?

$A$ man bought $500$ metres of electronic wire at $50$ paise per metre. He sold $50 \%$ of it at a profit of $5 \%$. At what percent should he sell the remainder so as to gain $10 \%$ on the whole transaction?

$A$ shopkeeper allows $23 \%$ commission on his advertised price and still makes a profit of $10 \%$. If he gains $₹ 56$ on one item,what is the advertised price of the item in $₹$?

$A$ shopkeeper bought $30 \text{ kg}$ of wheat at the rate of $₹ 45$ per $\text{kg}$. He sold $40\%$ of the total quantity at the rate of $₹ 50$ per $\text{kg}$. Approximately,at what price per $\text{kg}$ should he sell the remaining quantity to make $25\%$ overall profit? (in $₹$)

$A$ vendor bought toffees at $6$ for a rupee. How many for a rupee must he sell to gain $20 \%$?

If a commission at the rate of $10 \%$ is given to a bookseller on the marked price of a book by the publisher,the publisher gains $20 \%$. If the commission is increased to $15 \%$ then the gain percent would be