The last two conditions are:
10. Appointments may use any quantity of each supply.
11. Each supply may be used on zero or more appointments.
For instance, appointment 1 might use 2 disposable x-ray holders and 5 x-ray film units. Appointment 2 might use 1 x-ray holder and 1 film unit. Appointment 3 might not use any supplies.
Conditions 10 and 11 mean that you need to track the quantity of each supply used by each appointment. You need to keep track of 2 and 5 for the first appointment and 1 and 1 for the second appointment. There is nothing to keep track of for the third appointment.