If the selling price of $50$ articles is equal to the cost price of $40$ articles, then the loss or gain percent is 

A sells an article to $B$ making a profit of $\frac{1}{5}^{t h}$ his outlay. $B$ sells it to $C,$ gaining $20 \%$. If $C$ sells it for $Rs.\, 600$ and incurs a loss of $\frac{1}{6}^{t h}$ his outlay, the cost price of $A$ is (in $Rs.$)

Maninder bought two horses at $Rs.\, 40,000$ each. He sold one horse at $15 \%$ gain, but had to sell the second horse at a loss. If he had suffered a loss of $Rs.3,600$ on the whole transaction, then the selling price of the second horse is (in $Rs.$)

Some articles were bought at $6$ for $Rs. 5$ and sold at $5$ for $Rs. 6 .$ Gain percent is

If the selling price of $\frac{2}{3}$ of a certain quantity of milk be equal to the cost price of whole milk, then what will be the gain percent in this transaction?

$X$ sells two articles for $Rs.\, 4,000$ each with no loss and no gain in the interaction. If one was sold at a gain of $25 \%$ the other is sold at a loss of........$\%$