i dont understand this question can someone help!

Question

There are 1000 students in a high school. Among the 1000 students, 250 students take AP Statistics, and 300 students take AP French. 100 students take both AP courses. Let S be the event that a randomly selected student takes AP Statistics, and F be the event that a randomly selected student takes AP French.

 

a.Provide a written description of the complement event of (S OR F).
b. What is the probability of complement event of (S OR F)?

Answer 1

A Venn diagram is a very nice way to present this data and to determine that

# who take AP Stats but not AP French = 150

# who take AP French but not AP Stats = 200

# who take both is (given) 100

Therefore all others (who took neither, i.e. represented by (S∪F)' ) total 550.

P( (S∪F)' ) = 550/1000 = 0.55

Answer 2

So S Or F means all students taking  S and all students taking French It is the union of the two groups. So its complement whihc means not (the union of the two group) so all students who are taking neither AP F nor AP S