Problem
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?
The response should include a reference list. Double-space, using Times New Roman 12 pnt font, one-inch margins, and APA style of writing and citations.