If a shopkeeper sells $25$ articles at $Rs.\, 45$ per article after giving $10 \%$ discount and earns $50 \%$ profit. If the discount is not given the profit gained is in $\%$?

A fruitseller sells mangoes at the rate of $Rs.\, 9$ per $kg$ and thereby loses $20 \% .$ At what price per kg he should have sold them to make a profit of $5 \% ?$ (in $Rs.$)

A tradesman gives $4 \%$ discount on the marked price and gives $1$ book free for buying every $15$ books and thus gains $35 \% .$ The marked price is increased above the cost price by (appx.) (in $\%$)

A trader allows a trade discount of $20 \%$ and a cash discount of $6 \frac{1}{4} \%$ on the marked price of the goods and gets a net gain of $20 \%$ of the cost. By how much above the cost should the goods be marked for the sale? (in $\%$)

If a company sells a car with a marked price of $Rs$ $272000$ and gives a discount of $4 \%$ on $Rs$ $200000$ and $2.5\%$ on the remaining amount of $Rs$ $72000,$ then the actual price charged by the company for the car is (in $Rs.$)