If $5 \%$ more is gained by selling an article for $Rs. 350$ than by selling it for $Rs. 340$,the cost price of the article is:

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

The list price of a book is $Rs. 100$. $A$ dealer sells three such books for $Rs. 274.50$ after allowing a discount at a certain rate. Find the rate of discount in $\%$.

Profit earned by selling an article for $Rs. 1630$ is the same as the loss incurred by selling the article for $Rs. 1320$. What is the $CP$ in $Rs$?

$A$ shopkeeper sold some articles at $Rs. 35$ per piece and gained $40 \%$. What would be the selling price of each article to earn $60 \%$ profit? (in $Rs.$)

$A$ retailer offers the following discount schemes for buyers on an article:
$I.$ Two successive discounts of $10 \%$
$II.$ $A$ discount of $12 \%$ followed by a discount of $8 \%$
$III.$ Successive discounts of $15 \%$ and $5 \%$
$IV.$ $A$ discount of $20 \%$
The selling price will be minimum under the scheme: