$A$ man gains $20 \%$ by selling an article for a certain price. If he sells it at double the price,what will be the percentage of profit (in $\%$)?

$A$ discount series of $10 \%$,$20 \%$,and $40 \%$ is equal to a single discount of.......$\%$

The value of an article depreciates every year at the rate of $10 \%$ of its value. If the present value of the article is $Rs. 729$,then its worth $3$ years ago was (in $Rs.$)

An item costing $Rs. 200$ is being sold at $10 \%$ loss. If the price is further reduced by $5 \%$,the selling price will be (in $Rs.$)

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

Rehaan purchased a bike for $Rs. 54,000$. He sold it at a loss of $8\%$. With that money, he again purchased another bike and sold that at a profit of $10\%$. What is his overall loss or profit?