Answer:
P(A) = 0.2, P(B) = 0.5, P(A\B) = 0.3:
P(A\B) = P(A and B) P(B)
0.3 = P(A and B) 0.5
0.15 P(A and B)
P(A and B) = 0.15
B. P(A or B) = P(A) + P(B) - P(A and B)
0.2 + 0.5 - 0.15
0.70 - 0.15 = 0.55
4.6m questions
5.9m answers