Answer:
20
Explanation:
You would set up a proportion in order to solve this
3 green 12 green
------------ = ------------
8 total x total
Then you would cross mulitply for x and get 32. Since that is the total number, you would have to subract the 12 from 32 to get 20.
I'd say everything can be used but only what is needed for particular patient.
I think it is A. People would expect Ed to be a lawyer since his parents are lawyers as well.