Operations with sets. Examples of formulas in algebra of sets

Example 1

А — the sets of students, passed physics and mathematics on marks 4 or 5;

B — the sets of students with red hair;

С — the sets of students going in for sport.

Wich students contain in the set ?

These are not red students with marks 4 or 5, who are not going in for sport, or red students with mark 3, who are not going in for sport.