On an order of $5$ dozen boxes of a consumer product,a retailer receives an extra dozen free. This is equivalent to allowing him a discount of........$\%$

$A$ man sells two articles for $Rs. 5000$ each,neither losing nor gaining in the deal. If he sold one of them at a gain of $25 \%$,the other article is sold at a loss of .......$\%$

If the cost price of $12$ pens is equal to the selling price of $8$ pens,find the gain percent.

Gita buys a plot of land for $Rs. 96,000$. She sells $\frac{2}{5}$ of it at a loss of $6\%$. She wants to make a profit of $10\%$ on the whole transaction by selling the remaining land. The gain percentage on the remaining land is

$A$ dishonest dealer professes to sell his goods at cost price but uses a weight of $960 \, g$ instead of a $1 \, kg$ weight. Find his gain $\%$. (in $\%$)

The difference between successive discounts of $40\%$ followed by $30\%$ and $45\%$ followed by $20\%$ on the marked price of an article is $Rs. 12$. The marked price of the article is (in $Rs.$)