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

An article is sold for $Rs.\,4950$ at a gain of $10 \% .$ What would have been the gain or loss per cent if it had been sold for $Rs$ $4275 ?$

A retailer offers the following discount schemes for buyers on an article

$I.$ Two successive discounts of $10 \%$

$II.$ A discount of $12 \%$ followed by a discount of $8 \%$

$III.$ Successive discounts of $15 \%$ and $5 \%$

$IV.$ A discount of $20 \%$

The selling price will be minimum under the scheme

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

When a producer allows $36 \%$ concession on the retail price of his product, he earns a profit of $8.8 \% .$ What would be his profit percent if the commission is reduced by $24 \% ?$

A shopkeeper expects a gain of $22 \frac{1}{2} \%$ on his cost price. If in a week, his sale was of $Rs. \,392$ what was his profit? (in $Rs$)