Abhishek makes a profit of $Rs.\,110,$ if he sells a certain number of pens he has at the price of $Rs.\, 2.5$ per pen and incurs a loss of $Rs.$ $55,$ if he sells the same number of pens for $Rs.$ $1.75$ per pen. How many pens does Abhishek have?

The profit earned by selling an article for $Rs. 832$ is equal to the loss incurred when the same article is sold for $Rs. 448.$ What should be the selling price for making $50\%$ profit? (in $Rs.$)

A man buys an article for $10 \%$ less than its value and sells it for $10 \%$ more than its value. His gain or loss percent is

$'A'$ bought a certain quantity of oranges at total cost of $Rs.\, 1200 /-$ He sold $1 / 3^{\text {rd }}$ of those oranges at $20 \%$ loss. If $A$ earns an overall profit of $10 \%,$ at what percent profit did $A$ sell the rest of the oranges?

An article is sold at a profit of $20 \%$. If both the cost price and selling price are $RS.\, 150$ less, profit would be $5 \%$ more. Find the cost price.

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