"No students are athletes" but "some teachers are both athletes and students"

Question

I was reading some logical test here. I reported it down below

Given the following premises, state whether the conclusions are true, false, or unknown:

All athletes are coaches, but not all coaches are athletes. All coaches live in Chicago. No students are athletes, but all students are coaches. Some teachers are both athletes and students. Some parents are teachers, but no parents are students or athletes.

4. All parents live in Chicago.

A) True

B) False

C) Uncertain

5. All coaches are students.

A) True

B) False

C) Uncertain

however if "No students are athletes", I don't understand how "some teachers are both athletes and students".