$A$ man buys $10$ articles for $Rs. 8$ and sells them at $Rs. 1.25$ per article. His gain percent is

If a shopkeeper sells $25$ articles at $Rs. 45$ per article after giving $10 \%$ discount and earns $50 \%$ profit. If the discount is not given,what is the profit percentage gained?

On a $Rs. 10,000$ payment order,a person has a choice between three successive discounts of $10\%, 10\%$ and $30\%$ and three successive discounts of $40\%, 5\%$ and $5\%$. By choosing the better offer,how much can he save in $Rs.$?

The difference between a discount of $35 \%$ and two successive discounts of $20 \%$ on a certain bill was $Rs$ $22$. Find the amount of the bill in $Rs$.

By selling an article for $Rs. 21$,a man incurs a loss such that the percentage loss is equal to the cost price. The cost price of the article is (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.
$I.$ $3x^2 - 13x + 12 = 0$
$II.$ $2y^2 - 15y + 28 = 0$