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

$A$ shopkeeper sells an article at a gain of $10 \%$. Had he sold it at a loss of $20 \%$,its selling price would have been $Rs. 180$ less. What is the cost price of the article? (in $Rs.$)

If a vendor sells a coconut at $Rs. 14.4$,he makes a $10 \%$ loss. If he wants to make a $25 \%$ profit,at what price (in $Rs.$) should he sell it?

The price of $12$ chairs and $8$ tables is $Rs. 676$. What is the price of $21$ chairs and $14$ tables in $Rs.$?

$A$ man sells an article at $5 \%$ above its cost price. If he had bought it at $5 \%$ less than what he had paid for it and sold it at $Rs. 2$ less,he would have gained $10 \%$. The cost price of the article is (in $Rs.$)

$A$ dealer sold two types of goods for $Rs. 10,000$ each. On one of them,he lost $20 \%$ and on the other he gained $20 \%$. His gain or loss per cent in the entire transaction was