I sold a pair of shoes last week a \$150.00. The cost is \$100. My profit margin for last week is 33% (Revenue - Cost) / Revenue
What if the customer returned the shoes? Is my profit margin $0$ or negative? (Revenue - Cost) / Revenue?
What if I sold 3 pairs of shoes to a customer at \$150.00 each. (The cost of each is $100)... and the customer returned 1 pair. How do I calculate my profit margin?