$A$ man bought apples at the rate of $6$ for $Rs. 20$ and sold them at $4$ for $Rs. 16$. His estimated profit $\%$ is

$A$ man purchased some eggs at $3$ for $Rs. 5$ and sold them at $5$ for $Rs. 12$. Thus,he gained $Rs. 143$ in all. The number of eggs he bought is:

$A$ man gains $20 \%$ by selling an article for a certain price. If he sells it at double the price,what will be the percentage of profit (in $\%$)?

$A$ person sells $36$ oranges for $₹ 1$ and makes a loss of $4 \%$. Find how many oranges per $₹ 1$ should be sold to have a gain of $8 \%$.

$A$ 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 price of an article is raised by $30 \%$ and then two successive discounts of $10 \%$ each are allowed. Ultimately,the price of the article is