Microeconomics 1st Edition by Dean Karlan,Jonathan Morduch

Exercise 2

Lisa is a self-employed physical therapist who works from a rented space. Lisa charges $250 for a therapy session. She incurred the following costs last month: space and equipment rental, $1,200; wages, $3,500; materials, $1,800. If Lisa's profit last month was $2,000, how many clients did she see?