You want to start a business selling shoes. The shoes cost $30 to
a
make as well as a $50 delivery fee from the company. You are
planning to sell the shoes for $45 each.

QUESTIONS:

Write a function that represents the cost to make the shoes.
Write a function that represents the revenue from selling the shoes.
Write a function that represents the profit from selling the shoes.
How many shoes will you have to sell to make profit?