Respostas

2014-03-18T22:51:46-03:00
n(A) = 32
n(B) = 20
n(A ∩ B) = 10

n(A U B) = n(A) + n(B) - n(A ∩ B)  
n(A U B) = n(A) + n(B) - n(A ∩ B) =>
n(A U B) = 32 + 20 – 10 =>
n(A U B) = 42
U – n(A U B) = 50 – 42 = 8

8 alunos não praticam nem vôlei e nem futebol
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