Pedro sells wooden children's furniture at a crafts market. he charges $65 for a chair. the materials for a chair cost $45 and there is a $75 fee for a booth at the market. how many chairs must he sell to make a profit?

The answer is 4. Let's analyze that question. Firstly, it costs 75 dollars for a booth at the market. This fee is a one time fee. The materials for each chair is 45 dollars, meaning that the price that he's selling it for leaves 20 dollars ( 65 dollars, selling price - 45 dollars, materials price). So, he makes 20 dollars from each chair. However, we still have to pay off the fee. So, we must find how many times we need to multiply 20 dollars until it matches or cancels out the fee (75 dollars). That would be 20 * 4 = 80.