A school vending machine sells cartons of milk and juice. On a typical day:
No cartons are sold between 7 A. M. and
8 A. M., or from 5 P. M. onward.
The machine has a capacity of 100 cartons.
At 7 A. M., it is three-quarters full.
From 8 A. M. to 10 A. M., 10:15 A. M. to noon, and
from 1
1 p. M. to 3 P. M. the students are in class.
The machine is filled at 11 A. M. and at 4 P. M.
Sketch a graph of the number of cartons in the
vending machine as a function of time. Explain
what each section of the graph represents.