Questions: Events A and B are mutually exclusive. Suppose event A occurs with a probability of 0.15 and event B occurs with a probability of 0.4.
Compute the following.
(a) Compute the probability that B occurs but A does not occur.
(b) Compute the probability that either A occurs without B occurring or B occurs without A occurring.
Transcript text: Events $A$ and $B$ are mutually exclusive. Suppose event $A$ occurs with probability 0.15 and event $B$ occurs with probability 0.4 .
Compute the following.
(a) Compute the probability that $B$ occurs but $A$ does not occur.
(b) Compute the probability that either $A$ occurs without $B$ occurring or $B$ occurs without $A$ occurring.
Solution
Solution Steps
To solve the given problems, we need to use the properties of mutually exclusive events and basic probability rules.
(a) Since events \(A\) and \(B\) are mutually exclusive, the probability that \(B\) occurs but \(A\) does not occur is simply the probability of \(B\) occurring, because \(A\) and \(B\) cannot occur together.
(b) The probability that either \(A\) occurs without \(B\) occurring or \(B\) occurs without \(A\) occurring is the sum of the probabilities of \(A\) and \(B\) occurring, since they are mutually exclusive.
Step 1: Calculate the Probability that \(B\) Occurs but \(A\) Does Not Occur
Since events \(A\) and \(B\) are mutually exclusive, the probability that \(B\) occurs but \(A\) does not occur is given by:
\[
P(B \cap \neg A) = P(B) = 0.4
\]
Step 2: Calculate the Probability that Either \(A\) Occurs Without \(B\) Occurring or \(B\) Occurs Without \(A\) Occurring
The probability that either \(A\) occurs without \(B\) occurring or \(B\) occurs without \(A\) occurring is the sum of the probabilities of \(A\) and \(B\):
\[
P(A \cap \neg B) + P(B \cap \neg A) = P(A) + P(B) = 0.15 + 0.4 = 0.55
\]
Final Answer
The answers to the sub-questions are:
(a) \(P(B \cap \neg A) = 0.4\)
(b) \(P(A \cap \neg B) + P(B \cap \neg A) = 0.55\)
Thus, the final answers are:
\[
\boxed{P(B \cap \neg A) = 0.4}
\]
\[
\boxed{P(A \cap \neg B) + P(B \cap \neg A) = 0.55}
\]