The price of $12$ chairs and $8$ tables is $Rs. 676$. What is the price of $21$ chairs and $14$ tables in $Rs.$?

$A$ shopkeeper sold an item at $10 \%$ loss after giving a discount equal to half the marked price. The cost price of the item is ......... of the marked price.

$A$ shopkeeper sells an article at a gain of $10 \%$. Had he sold it at a loss of $20 \%$,its selling price would have been $Rs. 180$ less. What is the cost price of the article? (in $Rs.$)

$A$ 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 $\%$)

$A$ shopkeeper gains $17 \%$ after allowing a discount of $10 \%$ on the marked price of an article. Find his profit percent if the article is sold at the marked price allowing no discount. (in $\%$)

$A$ shopkeeper purchased a chair marked at $₹ 600$ at two successive discounts of $15 \%$ and $20 \%$. He spent $₹ 28$ on transportation and sold the chair for $₹ 545$. His gain percent was: (in $\%$)