The graph shows the amount that Miracle Maid Service charges to clean a house. They charge a flat house visit fee plus an additional cost per room to clean a house. How much is the initial house visit fee?
(A) $10
(B) $20
(C) $30
(D) $4
In this case, the x-axis represents the number of rooms while the y-axis represents the cost of "x" number of rooms. Because the initial house visit fee has not yet included any rooms, we should be looking at x = 0 (also known as the y-intercept). The graph intercepts the y-axis halfway between 20 and 40.
Therefore, the initial house visit fee is $30