Q47
A speaks truth in 60% cases B speaks truth in 70% cases. The probability that they will way say the same thing while describing a single event, is-
A.
0.54
AnswerB.
0.56
C.
0.68
D.
0.94
E.
None of these
Answer: Option A
Solution
Answer: Option A
Solution:
Let = event that A speaks the truthAnd = event that B speaks the truth
Then,
P (A and B say the same thing) = P [(A speaks the truth and B speaks the truth) or (A tells a lie and B tells a lie)]
P [ or
P +
P (). P () + P () . P ()