If $11$ mangoes are bought for $Rs. 10$ and sold at $10$ for $Rs. 11$,what is the gain or loss percentage (in $\%$)?

$A$ shopkeeper sells rice at $10 \%$ profit and uses weight $30 \%$ less than the actual measure. His gain percent is

In these questions,two equations numbered $I$ and $II$ are given. You have to solve both the equations and mark the appropriate option.
$I$. $x^{2} = 16$
$II$. $2y^{2} - 17y + 36 = 0$

$A$ wholesaler had $200$ dozens of mangoes. He sold some of these mangoes at $20 \%$ profit and the rest at $10 \%$ profit,so that he made $13 \%$ profit on selling all the mangoes. How many mangoes (in dozens) did he sell at $20 \%$ profit?

The cash difference between the selling price of an article at a profit of $4 \%$ and $6 \%$ is $Rs. 3$. The ratio of the $2$ selling prices is?

$A$ 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?