Any proportional relationship will include (0, 0) as a possible (input, output) pair. Here, the one-time fee of $10 means the output for 0 hours is not 0, but is 10. That is (0, 10) is a pair in the relationship, not (0, 0).
If 6 pounds of meat serves 9 people, divide 6/9. This equals 0.666... aka 2/3. This decimal refers to how much of the meat each person gets. Multiply this decimal by 108 people. You get 72 pounds of meat.
