Engineering Board Exam Reviewer · Conditional Probability and Bayes' Theorem · medium
Given P(A)=0.5, P(B A)=0.4, and P(B A')=0.2, find P(B).
- 0.4
- 0.6
- 0.2
- 0.3
Answer
D. 0.3
Solution
P(B)=P(B A)P(A)+P(B A')P(A')=0.4(0.5)+0.2(0.5)=0.3.
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