The cost price of $40$ articles is the same as the selling price of $25$ articles. Find the gain percent.

A shopkeeper sells $25$ articles at $Rs.\, 45$ per article after giving $10 \%$ discount and earns $50 \%$ profit. If the discount is not given, the profit gained is......$\%$

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?

A manufacturer sells an article to a wholesale dealer at a profit of $10 \%$. The wholesale dealer sells it to a shopkeeper at $20 \%$ profit. The shopkeeper sells it to a customer for $Rs.\, 56,100$ at a loss of $15 \%$. Then the cost price of the article to the manufacturer is (in $Rs.$)

A fruit-seller buys some oranges and by selling $40 \%$ of them he fealises the cost price of all the oranges. As the oranges being to grow over-ripe, he reduces the price and sells $80 \%$ of the remaining oranges at half the previous rate of profit. The rest of the oranges being rotten are thrown away. The overall percentage of profit is

cost price of $100$ books is equal to the selling price of $60$ books. The gain percentage or less percentage is