On selling an article for $Rs. 170$,a shopkeeper loses $15\%$. In order to gain $20\%$,he must sell that article at rupees:

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 wishes to give $5 \%$ commission on the marked price of an article but also wants to earn a profit of $10 \%$. If his cost price is $₹ 95$,then the marked price is (in $₹$):

Sardar Singh bought $200$ dozen oranges at $Rs. 10$ a dozen. He spent $₹500$ on transportation. He sold them at $Rs. 1$ each. What was his profit or loss percent?

$A$ shopkeeper allows a discount of $10 \%$ on the marked price of a camera. The marked price of the camera,which costs him $₹ 600$,to make a profit of $20 \%$ should be (in $₹$):

$A$ merchant buys $4000 \, kg$ of wheat,one-fifth of which he sells at a gain of $5 \%$,one-fourth at a gain of $10 \%$,one-half at a gain of $12 \%$,and the remainder at a gain of $16 \%$. If he had sold the whole at a gain of $11 \%$,he would have made $Rs. 72.80$ more. What was the cost price of the crop per $kg$? (in $Rs.$)