Looks like among the 2080, there are a total of 680+350+70 people had head exams. Can you answer a)?
In part 2, It is the conditional probability of head exams given that it is referred from A&E. And there are 680 out of (680+350+70).
I am not so sure because of some of the terminologies used in the question, so let's see if someone else has a thought.
#2) Sorry, Same here. Not familiar with the wording.