Question

You spend $35 setting up a lemonade stand. It costs you $0.30 in supplies. To make each glass you charge $.75. How many glasses of lemonade do you have to sell to break even?

Answer 1

Let $x$ be a number of glasses you need to sell to break even.

It means that:

$(0.75-0.30)x=35,$ where $0.75-0.30=0.35$ is a profit for one glass of lemonade

$0.35x=35$

$x=\frac{35}{0.35}=100$

Answer: 100 glasses.