Final answer:
A 7 unit appointment is equivalent to 70 minutes.
Step-by-step explanation:
To convert from time units to minutes, you need to know the conversion factor. In this case, the appointment book is divided into 6 time units per hour. So, each time unit represents 10 minutes (60 minutes divided by 6 units). Therefore, a 7 unit appointment is equivalent to 70 minutes (7 units multiplied by 10 minutes).