$A$ sells an article to $B$ at $15 \%$ profit. $B$ sells it to $C$ at $10 \%$ loss. If $C$ pays $₹ 517.50$ for it,then $A$ purchased it at:

$A$ vendor started selling vegetables at $Rs. 10$ per $kg$,but could not find buyers at this rate. So,he reduced the price to $Rs. 8.10$ per $kg$,but uses a faulty weight of $900\, g$ for $1\, kg$. Find the percent change in the actual price or loss. (in $\%$)

If the ratio of the cost price and selling price of an article is $20: 21$,then what will be the profit percent (in $\%$)?

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

By selling an article for $Rs. 384$,a trader gains $20 \%$. Find the cost price of the article.

$A$ dealer buys a table listed at $Rs. 1,500$ and gets successive discounts of $20 \%$ and $10 \%$. He spends $Rs. 20$ on transportation and sells it at a profit of $20 \%$. Find the selling price of the table (in $Rs.$).