Aditya bought $200$ dozen oranges at $Rs. 10$ per dozen and he spent $Rs. 500$ on transportation. He sold each orange at $Rs. 1$ each. What was his profit or loss $\%$?

Arun purchased $30 \, kg$ of wheat at the rate of $Rs. \, 11.50$ per $kg$ and $20 \, kg$ of wheat at the rate of $Rs. \, 14.25$ per $kg$. He mixed the two and sold the mixture. Approximately at what price per $kg$ should he sell the mixture to make $30 \%$ profit? (in $Rs.$)

If a shopkeeper wants to give a $20 \%$ discount on a toy, he has to sell it for $Rs. 300$. If he sells it at $Rs. 405$, then his gain percent is: (in $\%$)

While selling a watch,a shopkeeper gives a discount of $15 \%$. If he gives a discount of $20 \%$,he earns $Rs. 51$ less as profit. What is the original price of the watch? (in $Rs$)

$A$ shopkeeper sells $25$ articles at $Rs. 45$ per article after giving a $10 \%$ discount and earns a $50 \%$ profit. If no discount is given,the profit percentage gained is......$\%$

If a commission at the rate of $10 \%$ is given to a bookseller on the marked price of a book by the publisher,the publisher gains $20 \%$. If the commission is increased to $15 \%$ then the gain percent would be