$A$ dealer allows a discount of $15 \%$. $A$ customer pays an amount of $Rs. 318.75$ for an article. At what price is the article listed? (in $Rs.$)

$A$ shopkeeper gives two successive discounts of $7 \%$ each on the marked price of $Rs.\, 20,000$ of an article. The selling price of the article is (in $Rs.$):

The simple interest and the true discount on a certain sum for a given time and at a given rate are $Rs.\, 85$ and $Rs.\, 80$ respectively. The sum is (in $Rs.$)

At what percent above the cost price must a person mark the price of an article so that he can enjoy $20 \%$ profit after allowing $20 \%$ discount?

If the banker's discount on a certain sum in $2$ years at a certain rate is $Rs. 150$ and the simple interest on the same sum in $3$ years is $Rs. 240$,find the sum (in $Rs.$) and the rate of interest (in $\%$).

$A$ 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 $Rs.$)?