Question

a man buys a dozen cameras for $1800. He sells them at a profit of $36 each. Express his profit as a percentage of his selling price. ​

Answer 1

First of all, we need to deduce the price of a single camera:

$\dfrac{1800}{12}=150$

Now, we know that he profits 36 dollars from each camera. So, we are asking: which percentage of 150 is 36? We have

$36 = 150\cdot\dfrac{x}{100}$

This equation literally says: 36 is x-percent of 150. And we need to solve for x:

$x=\dfrac{36\cdot 100}{150} =24$