$A$ vendor bought toffees at $6$ for a rupee. How many for a rupee must he sell to gain $20 \%$?

$Mr.$ $A$ sold goods to $Mr.$ $B$ at a $10\%$ discount on the printed rate. The discounted value is $Rs. 1242$. If a $15\%$ profit is earned on the purchase rate by selling the goods at the printed rate,what is the purchase rate? (in $Rs.$)

Divyam bought an article with $15 \%$ discount on the labelled price. He sold the article with $10 \%$ profit on the labelled price. What was his percent profit on the price he bought?

$A$ shopkeeper purchased $70$ $kg$ of potatoes for $Rs. 420$ and sold the whole lot at the rate of $Rs. 6.5$ per $kg$. What will be his gain percent?

The printed price of an article is $40 \%$ higher than its cost price. What is the discount rate so that the seller gains a $12 \%$ profit?

$A$ sells an article to $B$ at a profit of $20 \%$ and $B$ sells it to $C$ at a loss of $10 \%$. If $C$ pays $Rs. 540$ for it,at what price did $A$ buy?