$A$ pen was sold for a certain sum and there was a loss of $20 \%$. Had it been sold for $Rs. 12$ more,there would have been a gain of $30 \%$. What would be the profit percentage if the pen was sold for $Rs. 4.80$ more than the original selling price?

Mr. Verma sold his scooter for $Rs. 10500$ at a gain of $5 \%$. Find out the cost price of the scooter (in $Rs.$).

If cost price is $Rs. 150$ less than the selling price and profit is $20 \%$,then what is the selling price (in $Rs.$)?

The cost price of $6$ pens is equal to the selling price of $4$ pens. Find the profit percent. (in $\%$)

$A$ bakery bakes cakes with the expectation that it will earn a profit of $40 \%$ by selling each cake at the marked price. During delivery to the showroom, $16 \%$ of the cakes were completely damaged and could not be sold. $24 \%$ of the cakes were slightly damaged and were sold at $80 \%$ of the cost price. The remaining $60 \%$ of the cakes were sold at the marked price. What is the percentage profit on the whole consignment (in $\%$)?

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