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

A rice trader buys $16$ quintals of rice for $Rs.\, 5632$. $20 \%$ rice is lost in transportation. At what rate should he sell to earn $25 \%$ profit in $Rs.$ per quintal?

A shopkeeper buys $144$ items at $90$ paisa each. On the way $20$ items are broken. He sells the remainder at $RS.\,1.20$ each. His gain percent correct to one place of decimal is

A man bought apples at the rate of 6 for $Rs.\,20$ and sold them at $4$ for $Rs.\, 16.$ His estimated profit $\%$ is

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?

If the $CP$ of $50$ items is equal $SP$ of $40$ items then what is the profit or loss $\% ?$