Nisha bought a number of oranges at $2$ for a rupee and an equal number at $3$ for a rupee. To make a profit of $20 \%$ she should sell a dozen for (in $Rs.$)

By selling an article for $Rs$ $384,$ a trader gains $20 \%$. Find the cost price of article.

A shopkeeper buys a toy at $Rs.\,100$ and sells it at $Rs.$ $125 .$ Another shopkeeper buys the same toy at $Rs.\, 125$ but sells it at $Rs.$ $100 .$ What are the respective profit and loss percentages for the two shopkeepers.

A dairyman pays $Rs.\, 6.40$ per litre of milk. He adds water and sells the mixture at $Rs.\, 8$ per litre, thereby making $37.5\%$ profit. The proportion of water to milk received by the customers is

Ajit caculates his profit percentage on the selling price whereas Rohit calculates his on the cost price. They find that the difference of their profits is $Rs.\, 100.$ If the selling price of both of them are the same and both of them get $25\%$ profit, find their selling price? (in $Rs.$)

Abhishek purchased $140$ shirts and $250$ trousers at $Rs.\, 450$ and at $Rs.\, 550$ respectively. What should be the overall average selling price of shirts and trousers so that $40 \%$ profit is earned? (in $Rs.$)

(rounded off to next integer)