Suppose we have events A and B so that P(A)=0.3 and P(B)=0.4 Find P(A or B) if P(A|B)=0.2

Answer 1

Suppose we have events A and B so that P(A)=0.3 and P(B)=0.4 Find P(A or B) if P(A|B)=0.2

P(A∪B) = P(A) + P(B) – P(A∩B)

P(A∩B) = P(A|B) · P(B)

P(A∩B) = (0.2)(0.4) = 0.08

P(A∪B) = 0.3 + 0.4 – 0.08

P(A∪B) = 0.62