Bonjour,
a) P (A ∪ B) + P (A ∩ B) = P(A) + P(B)
P (A ∪ B) = P(A) + P(B) - P (A ∩ B)
0,3 + 0,5 - 0,1
= 0,8 - 0,1
= 0,9
P (A ∪ B) = 0,9
b) P (A ∪ B) + P (A ∩ B) = P(A) + P(B)
P (A ∩ B) = P(A) + P(B) - P (A ∪ B)
1/4 + 1/3 - 1/2
= 3/12 + 4/12 - 6/12
= 7/12 - 6/12
= 1/12
P (A ∩ B) = 1/12
c) P (A ∪ B) + P (A ∩ B) = P(A) + P(B)
P (A ∪ B) + P (A ∩ B) - P(A) = P(B)
20/27 + 2/27 - 1/9
= 22/27 - 3/27
= 19/27
P(B) = 19/27
N'hesite pas a poser des questions si tu ne comprends pas
Bonne journee !
