A fruit vendor buys $10$ bananas for $Rs.\, 14$ and sells them at $12$ for $Rs.\,15$. Find his percentage gain or loss.

An electric pump was sold at a profit of $15 \% .$ Had it been sold.for $Rs.\, 600$ , the profit would have been $20 \% .$ The former selling price is in $Rs.?$

A sells an article to $B$ at a gain of $20 \%$ and $B$ sells it to $C$ at a gain of $10 \%$ and $C$ sells it to $D$ at a gain of $12 \frac{1}{2} \% .$ If $D$ pays $Rs.\, 29.70,$ then $A$ purchased the article for (in $Rs.$)

Hundred oranges are bought at the rate of $Rs.\, 350$ and sold at the rate of $Rs.\, 48$ per dozen. The percentage of profit or loss is 

A shopkeeper sold Chairs at $Rs.\, 2139$ each after giving $7 \%$ discount on labelled price. Had he not given the discount, he would have earned a profit of $15 \%$ on the cost price. What was the cost price of each chairs? (in $Rs.$)

If the selling price of an article is $\frac{4}{3}^{rd}$ of its cost price the profit in the transaction is $\%$