Probability Question 254
Question: Let A and B are two events and $ P({A}’)=0.3 $ , $ P(B)=0.4,P(A\cap {B}’)=0.5 $ , then $ P(A\cup {B}’) $ is
[Orissa JEE 2005]
Options:
A) 0.5
B) 0.8
C) 1
D) 0.1
Show Answer
Answer:
Correct Answer: B
Solution:
$ P({A}’)=0.3 $ , $ P(A)=0.7 $
$ P({B}’)=0.6 $ ,
$ \therefore $ $ P(B)=0.4 $ and $ P(A\cap {B}’)=0.5 $
$ \therefore $ $ P(A\cup {B}’)=P(A)+P({B}’)-P(A\cap {B}’) $ = 0.7 + 0.6 - 0.5 = 0.8.
BETA
