Question

If p(a) = 0.50, p(b) = 0.60, and p(a intersection

b.= 0.30, what is the p(a union b)? enter your answer as a decimal rounded to two places.

Answer 1

Use the identity P(A ∪ B) = P(A)+P(B)-P(A ∩ B)

P(A)=0.50
P(B)=0.60
P(A ∪ B) = 0.30
=>
P(A ∪ B) = P(A)+P(B)-P(A ∩ B)
=(0.50+0.60)-0.30
=0.80