Q. 7
Let A and B be two mutually exclusive events of a random experiment such that P(not A) = 0.65 and P(A or B) = 0.65, find P(B).
Answer :
Given : A and B are mutually exclusive events
P(not A) = P() = 0.65 , P(A or B) = 0.65
To find : P(B)
Formula used : P(A) = 1 – P()
P(A or B) = P(A) + P(B) - P(A and B)
For mutually exclusive events A and B, P(A and B) = 0
P(A) = 1 – P(not A)
P(A) = 1 – 0.65
P(A) = 0.35
Substituting in the above formula we get,
0.65 = 0.35 + P(B)
P(B) = 0.65 – 0.35
P(B) = 0.30
P(B) = 0.30
Rate this question :


If A and B are mutually exclusive events, then
Mathematics - ExemplarState whether the statements are True or False
The probability of an occurrence of event A is .7 and that of the occurrence of event B is .3 and the probability of occurrence of both is .4.
Mathematics - ExemplarIf P (A ∪ B) = P (A ∩ B) for any two events A and B, then
Mathematics - ExemplarState whether the statements are True or False
The probability of intersection of two events A and B is always less than or equal to those favourable to the event A.
Mathematics - Exemplar