$A$ shopkeeper buys articles at $8$ for $Rs\,16$ and sells them at $9$ for $Rs\,20$. What is his gain or loss percent?

$A$ loss of $19 \%$ gets converted into a profit of $17 \%$ when the selling price is increased by $Rs. 162$. Find the cost price of the article in $Rs.$

If an item is sold for $Rs. 924$,there is a profit of $10\%$. What is the cost price?

$P$ invests $Rs. 9100$ for $3$ months. $Q$ invests $Rs. 6825$ for $2$ months and $R$ invests $Rs. 8190$ for $5$ months in a business. If the total profit amounts to $Rs. 4158$,how much profit should $Q$ get? (in $Rs.$)

$A$ bakery bakes cakes with the expectation that it will earn a profit of $40 \%$ by selling each cake at the marked price. During delivery to the showroom, $16 \%$ of the cakes were completely damaged and could not be sold. $24 \%$ of the cakes were slightly damaged and were sold at $80 \%$ of the cost price. The remaining $60 \%$ of the cakes were sold at the marked price. What is the percentage profit on the whole consignment (in $\%$)?

Arun marks up the computer he is selling by $20 \%$ profit and sells them at a discount of $15 \%$. Arun's net gain percent is (in $\%$)