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

Nutan bought a watch with $24 \%$ discount. If she pays $Rs.\, 779$ for that watch then what is the marked price of watch in $Rs.$?

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

A man invests $Rs.\, 21,000$ in shares of a company. He sells one$-$third of total shares at a profit of $10 \% .$ But the remaining shares he has to sell at $5 \%$ loss. Find his overall profit or loss $\%.$

Allowing $20 \%$ and $15 \%$ successive discounts, the selling price of an article becomes $Rs.\,3,060;$ then the marked price will be (in $Rs.$)

A man bought nine pens for a rupee. How many pens should be sell for a rupee to gain $50 \% ?$