A shopkeeper buys a toy at $Rs.\,100$ and sells it at $Rs.$ $125 .$ Another shopkeeper buys the same toy at $Rs.\, 125$ but sells it at $Rs.$ $100 .$ What are the respective profit and loss percentages for the two shopkeepers.

The ratio between selling price and cost price of an article is $7: 5 .$ What is the ratio between the profit and the cost price of that article?

On selling an article for $Rs.\, 170,$ a shopkeeper loses $15 \% .$ In order to gain $20 \%,$ he must sell that article at rupees

A man sells two articles, each for $Rs.\,640.$ He earns $20 \%$ profit on the first, and $40 \%$ profit on the second. Find his overall percent profit.

Ravipurchases $90$ pens and sells $40$ pens at a gain of $10 \%$ and $50$ pens at a gain of $20 \% .$ Had he sold all of them at a uniform profit of $15 \%$ he would have got $Rs.\, 40$ less. Find the cost price of each pen in $Rs.$

A sells his house worth $Rs.\, 10\, lakh$ to $B$ at a loss of $10 \% .$ Later $B$ sells it back to $A$ at $10 \%$ profit. The result of the two transactions is