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

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 $Rs$)

After selling $5 \%$ of a quantity of sugar,$5 \text{ kg}$ of sugar remains. Find the total quantity of sugar in $\text{kg}$.

$A$ 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?

$A$ trader marked the price of his commodity so as to include a profit of $25 \%$. He allowed a discount of $16 \%$ on the marked price. His actual profit was (in $\%$):

$X$ sells two articles for $Rs. 4,000$ each with no loss and no gain in the transaction. If one was sold at a gain of $25\%$, the other is sold at a loss of ........$\%$.