$A$ dealer purchased an article for $Rs. 900$ and fixes the list price in such a way that he gains $20\%$ after allowing $10\%$ discount. What is the list price (in $Rs.$)?

$A$ photographer allows a discount of $10 \%$ on the advertised price of a camera. The price (in $Rs.$) that must be marked on the camera,which cost him $Rs.\, 600$,to make a profit of $20 \%$ would be

If the shopkeeper sells an item at $Rs. 960$ which is marked as $Rs. 1200$, what is the discount he is offering? (in $\%$)

The true discount on a bill of $Rs.\, 1260$ due for $6$ months at $10 \%$ per annum is (in $Rs.$):

$Rs.\, 20$ is the true discount on $Rs.\, 210$ due after a certain time. What will be the true discount on the same sum due after half of the former time,the rate of interest being the same? (in $Rs.$)

$A$ retailer gets a discount of $40 \%$ on the printed price of an article. The retailer sells it at the printed price. His gain percent is