Question
Question: If the probability for A to fail in an examination is 0.2 and that for B is 0.3, then the probabilit...
If the probability for A to fail in an examination is 0.2 and that for B is 0.3, then the probability that either A fails or B fails is
A
0.5
B
0.44
C
0.06
D
None of these
Answer
0.44
Explanation
Solution
Required probability = 1 – (neither A nor B fails)
= 1 – P (both A and B are successful)
= 1 – (1 – 0.2) (1 – 0.3)
= 1 – 0.8 x 0.7 = 0.44