In: Statistics and Probability
The formulas or concept that will be repeatedly used in this problem are
Probability of joint occurence is always zero, i.e.
Probability of joint occurence is the product of individual probabilities, i.e.
Hence, we can deal with them now
a. P(B occurs or A does not occur or both) = P(B occurs)
(because if B occurs, then it is evident that A will definitely not occur, so it is not a different condition)
= 0.36
b. P(A occurs without B occurring or B occurs without A occurring) = P(A) + P(B)
(again by definition of mutually eclusive, if one occurs then it is definite that other does not occur)
= 0.05 + 0.36 = 0.41
Event names are not mentioned in the question statement.
"If does not occur, what is the probability that occurs" could mean two different things.
It it actually means "If A does not occur, what is the probability that B occurs" then the answer is 0.81
It it actually means "If B does not occur, what is the probability that A occurs" then the answer is 0.11
If event A or event B occurs, what is the probability that B occurs?
First, we find the probability that either A or B occurs (the union)
Now we apply the conditional probability
"If does not occur, what is the probability that occurs" could again mean two things
If it means "If A does not occur, what is the probability that B occurs" then the answer is
If it means "If B does not occur, what is the probability that A occurs" then the answer is
P(A occurs but B does not occur) = P(A) * P(not B) = 0.69 * (1 - 0.75) = 0.1725
Second stateent is again ambiguous