By selling an umbrella for $Rs.\, 300,$ a shopkeeper gains $20 \%$. During a clearance sale, the shopkeeper allows a discount of $10 \%$ on the marked price. His gain per cent during the sale is

Sarita sells a Phone at a profit of $20 \% .$ If she had bought it at $20 \%$ less and sold it for $Rs.\, 180$ less, she would have gained $25 \%$. Find thé gost price of the Phone in $Rs.$

The cost price of $40$ articles is the same as the selling price of $25$ articles. Find the gain percent.

A trader marked his goods at $20 \%$ above the cost price. He sold half the stock at the marked price, one quarter at a discount of $20 \%$ on the marked price and the rest at a discount of $40 \%$ on the marked price. His total gain is.......$\%$

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

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