The profit earned by selling an article for $Rs. 900$ is double the loss incurred when the same article is sold for $Rs. 450$. At what price should the article be sold to make $25\%$ profit?

Aditya bought a scooter for a certain sum of money. He spent $15 \%$ of the cost price on repairs and sold it for a profit of $Rs. 1104$. What did he spend on repairs if the profit he earned was $20 \%$?

Suresh purchased a $TV$ set for $Rs. 11250$. He spent $Rs. 800$ on installation and $Rs. 150$ on transportation. At what price should it be sold so that the profit earned would be $15\%$,if no discount was offered? (in $Rs.$)

$A$ man bought oranges at the rate of $8$ for $Rs. 34$ and sold them at the rate of $12$ for $Rs. 57$. How many oranges should be sold to earn a net profit of $Rs. 45$?

If a radio is purchased for $Rs. 490$ and sold for $Rs. 465.50$,find the $\text{loss} \%$. (in $\%$)

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