Question

On a coordinate plane, a piecewise function has 3 lines. The graph shows cleaning time in hours on the x-axis and total cost in dollars on the y-axis. The first line has an open circle at (0, 50) and continues horizontally to a closed circle at (2, 50). The second line has an open circle at (2, 100) and continues horizontally to a closed circle at (6, 100). The third line has an open circle at (6, 200) and continues horizontally to a closed circle at (8, 200). The graph represents the cleaning costs charged by a housekeeping service. Which statement is true of the cost function? A cleaning time of 2 hours will cost $100. A cleaning time of 6 hours will cost $150. Cost is a fixed rate of $100 for jobs requiring more than 2 hours, up to a maximum of 6 hours. Cost is a fixed rate of $200 for jobs that require at least 6 hours.

Answer 1

Answer:

  C. (2, 6] hour jobs cost $100

Step-by-step explanation:

Let's consider each of these statements in view of the graph:

1. A cleaning time of 2 hours will cost $100. -- The closed circle at (2, 50) tells you the cost of a 2-hour job is $50, not $100.
2. A cleaning time of 6 hours will cost $150. -- The closed circle at (6, 100) tells you the cost of a 6-hour job is $100, not $150.
3. Cost is a fixed rate of $100 for jobs requiring more than 2 hours, up to a maximum of 6 hours. -- The line between the open circle at (2, 100) and the closed circle at (6, 100) tells you this is TRUE.
4. Cost is a fixed rate of $200 for jobs that require at least 6 hours. -- "At least 6 hours" means "greater than or equal to 6 hours." The closed circle at (6, 100) means a 6-hour job is $100, not $200.