$A$ man sold his two cars for $Rs. 4.5$ lakh each. In the sale of the first car, he incurred $20\%$ profit, and in the sale of the second, he incurred $20\%$ loss. What is the total amount of profit or loss?

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

$A$ shopkeeper sold an article offering a discount of $24 \%$ and earned a profit of $23.5 \%$. What would have been the percentage of profit earned if no discount had been offered?

$A$ bakery bakes cakes with the expectation that it will earn a profit of $40 \%$ by selling each cake at the marked price. During delivery to the showroom, $16 \%$ of the cakes were completely damaged and could not be sold. $24 \%$ of the cakes were slightly damaged and were sold at $80 \%$ of the cost price. The remaining $60 \%$ of the cakes were sold at the marked price. What is the percentage profit on the whole consignment (in $\%$)?

$A$ man bought $15$ mangoes for a rupee. How many mangoes were sold for a rupee so that there is a loss of $25 \% ?$

$A$ shopkeeper professes to sell his goods at cost price but uses a weight of $800 \text{ g}$ instead of a $1 \text{ kg}$ weight. His profit percentage is: