$A$ sells an article to $B$ at a profit of $20 \%$ and $B$ sells it to $C$ at a loss of $10 \%$. If $C$ pays $Rs. 540$ for it,at what price did $A$ buy?

$A$ plate was sold for $Rs. 6,300$ after giving two successive discounts of $12.5\%$ and $10\%$. Find the marked price (in $Rs.$).

Ramesh purchased a bicycle for $Rs. 5200$ and spent $Rs. 800$ on its repairs. He had to sell it for $Rs. 5500$. Find out his profit or loss percent.

$A$ vendor bought toffees at $6$ for a rupee. How many for a rupee must he sell to gain $20 \%$?

$A$ 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:

$A$ shopkeeper professes to sell his goods at cost price but uses a $930 \text{ g}$ weight instead of $1 \text{ kg}$ weight. What will be the profit percentage of the shopkeeper (in $\%$)?