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

Two toys are sold at $Rs. 504$ each. One toy brings the dealer a gain of $12 \%$ and the other a loss of $4 \%$. The gain or loss percent by selling both the toys is

$A$ shopkeeper allows a discount of $10\%$ on the marked price of an item but charges a sales tax of $8\%$ on the discounted price. If the customer pays $Rs. 3,402$ as the price including the sales tax,then the marked price is (in $Rs.$)

$A$ fan is listed at $Rs. 1500$ and a discount of $20 \%$ is offered on the list price. What additional discount must be offered to the customer to bring the net price to $Rs. 1104$? (in $\%$)

Amit buys $5$ watches for $Rs. 9450$ and later sells them for $Rs. 9700$. How much profit does Amit make per watch in $Rs.$?

$A$ shopkeeper bought $30\, Kg$ of wheat at the rate of $Rs.\, 45$ per $Kg$. He sold $40\%$ of the total quantity at the rate of $Rs.\, 50$ per $Kg$. Approximately,at what price per $Kg$ should he sell the remaining quantity to make $25\%$ overall profit? (in $Rs.$)