Nitin bought some oranges at $Rs.\, 40$ a dozen and an equal number at $\,30$ a dozen. He sold them at $Rs.\,45$ a dozen and made a profit of $\,480.$ The number of oranges, he bought, was

A shopkeeper marks his goods at $40 \%$ above their cost price. He is able to sell $\frac{3}{4}$ th of his goods at this price, and the remaining at $40 \%$ discount. Assuming that the shopkeeper is able to sell the goods he buys, find his loss or gain as $\%$ of the whole transaction.

A man sells an article at $5 \%$ above its cost price. If he had bought it at $5 \%$ less than what he had paid for it and sold it at $Rs.\, 2$ less, he would have gained $10 \% .$ The cost price of the article is (in $Rs.$)

A pen was sold for a certain sum and there was a loss of $20 \% .$ Had it been sold for $Rs.\, 12$ more, there would have been a gain of $30 \% .$ What would be the profit if the pen was sold for $Rs.\, 4.80$ more than what it was sold for? (in $\%$)

A shopkeeper has to sell $24\, Kg$ of sugar. He sells a part of these at a gain of $20 \%$ and the rest at a loss of $5 \% .$ If on the whole he earns a profit of $10 \%$, the amount of Sugar sold at a loss is in $Rs.$?

A trader mixes $26\, kg$ of rice at $Rs$. $20$ per $kg$ with $30\, kg$ of rice of other variety at $Rs.\, 36$ per $kg$ and sells the mixture at $Rs.\, 30$ per $kg.$ His profit percent is