$A$ trader buys $500 \, kg$ of cotton for $Rs. 9,000$. $10 \%$ of this cotton is spoiled due to rain. At what rate $(Rs./ kg)$ should he sell the rest to earn $10 \%$ profit?

$10 \%$ discount and then $20 \%$ discount in succession is equivalent to a total discount of $... \%$.

If Aditya sells an article to Nutan at $10 \%$ gain,while Nutan sells it to Manish at $20 \%$ gain at $Rs. 1914$,then what is the Cost Price in $Rs.$?

On an order of $5$ dozen boxes of a consumer product,a retailer receives an extra dozen free. This is equivalent to allowing him a discount of........$\%$

$A$ shopkeeper allows a discount of $10\%$ on the marked price of an item but charges a sales tax of $8\%$ on the discounted price. If the customer pays $Rs. 3,402$ as the price including the sales tax,then the marked price is (in $Rs.$)

By selling $90$ pens for $Rs. 80$,a man loses $20\%$. What should be the selling price (in $Rs.$) of $90$ pens for $20\%$ profit?