Mr. Wilson coaches the basketball team and the volleyball team. There are 15 members on the basketball team and 13 members on the volleyball team. Both teams are playing in a tournament at the same school and the coach orders a bus that fits 24 people.
The principle of inclusion and exclusion gives a formula for finding the number of items in the union of two or
more sets.
Two Sets:
n(A or B) = n(A)+n(B)-n(A and B) or n(A ∪ B)= n(A)+n(B)-n(A ∩ B)
Three Sets:
n(A ∪ B ∪ c) = n(A) + n(B) + n(c) – n(A ∩ B)- n(A ∩ c)-n(B ∩ c) + n(A ∩ B ∩ c)