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Mathematics>Standard Multiple Choice

Read the following SAT test question and then click on a button to select your answer.

P=100h-2000
Mia's law firm has $2000 worth of expenses each month. Her firm charges $100 per hour for legal advice. The given equation shows the firm's profit, P, after being paid for h hours of legal advice during a one-month period. What is the minimum number of hours of legal advice that Mia's firm must be paid for during one month in order to cover the firm's monthly expenses?

A.20 hours
B.80 hours
C.100 hours
D.200 hours

答案和解析

答案：A

解析：

Choice A is correct. If the firm only covers the monthly expenses, the profit will be zero. Substituting 0 for P in the given equation and solving for h will give the number of hours of legal advice the firm needs to be paid for in order to break even.

This can be written as: P=100h-2000 0=100h-2000 h=20