If the $CP$ of $50$ items is equal to the $SP$ of $40$ items,then what is the profit or loss $\%$ (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 $Rs.$)

On selling an article for $Rs. 170$,a shopkeeper loses $15\%$. In order to gain $20\%$,he must sell that article at rupees:

Mr. Kapur purchased two toy cycles for $Rs. 750$ each. He sold these cycles,gaining $6 \%$ on one and losing $4 \%$ on the other. The gain or loss percent in the whole transaction is

$A$ white goods dealer pays $10 \%$ custom duty on an iPhone that costs $Rs. 25000$ in $UK$. For how much should he mark it,if he desires to make a profit of $20 \%$ after giving a discount of $25 \%$ to the buyer? (in $Rs$)

An article is listed at $Rs. 65$. $A$ customer bought this article for $Rs. 56.16$ and received two successive discounts,of which one is $10 \%$. Find the other discount in this discount scheme offered by the shopkeeper (in $\%$).