Q. If the probability of $A$ to fail in an examination is 0.2 and that for $B$ is 0.3, then probability that either $A$ or $B$ is fail, is
A) 0.5
B) 0.44
C) 0.8
D) 0.25
Explanation
(b)
Here, $A$ and $B$ are independent events
$\therefore\ P(A \cap B) = P(A).P(B) = 0.06$
Now, $P(A \cup B) = P(A) + P(B) - P(A \cap B)$
$= 0.2 + 0.3 - 0.06 = 0.44$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.