Question

Find the indicated probability.
If P(A or B) = 0.8, P(A) = 0.4, and P(A and B)= 0.15, find P(B).
P(B)=
(Simplify your answer. Type an integer or a decimal.)

Answer 1

Answer:

$P(B) = 0.55$

Step-by-step explanation:

Given

$P(A\ or\ B) = 0.8$

$P(A) = 0.4$

$P(A\ and\ B) = 0.15$

Required

Find P(B)

In probability, we have:

$P(A\ or\ B) = P(A) + P(B) - P(A\ sd B)$

Substitute values

$0.8 = 0.4 + P(B) - 0.15$

Collect Like Terms

$P(B) = 0.8 - 0.4 + 0.15$

$P(B) = 0.55$