If cost price is $Rs. 150$ less than the selling price and profit is $20 \%$,then what is the selling price (in $Rs.$)?

If eggs are bought $12$ for $Rs. 10$ and sold at $10$ for $Rs. 12$,what is the gain or loss $\%$?

While selling a watch,a shopkeeper gives a discount of $15 \%$. If he gives a discount of $20 \%$,he earns $Rs. 51$ less as profit. What is the original price of the watch? (in $Rs$)

$A$ shopkeeper sold chairs at $Rs. 2139$ each after giving a $7 \%$ discount on the 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 chair? (in $Rs.$)

$A$ businessman allows a discount of $10 \%$ on the marked price. What percent above the cost price must he mark his goods to make a profit of $17 \% ?$

$A$ man buys an article for $Rs. 27.50$ and sells it for $Rs. 28.60$. Find the gain percent. (in $\%$)