$A$ plate was sold for $Rs. 6,300$ after giving two successive discounts of $12.5\%$ and $10\%$. Find the marked price (in $Rs.$).

The profit earned by selling an article for $Rs. 900$ is double the loss incurred when the same article is sold for $Rs. 450$. At what price should the article be sold to make $25\%$ profit?

At a cost of $60$ paise per article,Sarika produces $750$ articles. She sets the selling price such that if only $600$ articles are sold,she would have made a profit of $40 \%$ on the total outlay. However,$120$ articles got spoilt and she was able to sell $630$ articles at this price. Find her actual profit or loss percent as a percentage of the total outlay,assuming that the unsold articles are useless.

Paras Health Care made $3000$ strips of vitamin tablets at a cost of $Rs. 4800$. The company gave away $1000$ strips of tablets to doctors as free samples. $A$ discount of $25\%$ is given on the printed price. Find the ratio of profit in $Rs.$ if the price is raised from $Rs. 3.25$ to $Rs. 4.25$ per strip and if at the latter price,samples to doctors were done away with.

$A$ person purchases $8$ pens for ₹ $10$ and sells $10$ pens for ₹ $8$. How much profit or loss percentage does he make?

$A$ dishonest dealer defrauds to the extent of $x \%$ in buying as well as selling his goods by using faulty weight. What will be the gain per cent on his outlay?