Prob Mutually Exclusive
1. **Understanding the problem:**
We have mutually exclusive events $A$ and $B$ in the sample space $2^\Omega$. We want to find the probability of $\overline{A} \cap \overline{B}$, which means the event that neither $A$ nor $B$ occurs.
2. **Recall definitions:**
- Since $A$ and $B$ are mutually exclusive, $A \cap B = \emptyset$.
- The complement $\overline{A}$ is the event that $A$ does not occur.
- Similarly, $\overline{B}$ is the event that $B$ does not occur.
- The event $\overline{A} \cap \overline{B}$ means both $A$ and $B$ do not occur.
3. **Use set identity:**
We know De Morgan's law:
$$\overline{A} \cap \overline{B} = \overline{A \cup B}$$
4. **Calculate the probability:**
Since $A$ and $B$ are mutually exclusive,
$$P(A \cup B) = P(A) + P(B)$$
Therefore,
$$P(\overline{A} \cap \overline{B}) = P(\overline{A \cup B}) = 1 - P(A \cup B) = 1 - [P(A) + P(B)]$$
5. **Check given options:**
- $P(A)$ is just the probability of $A$.
- $P(B)$ is just the probability of $B$.
- $P(\overline{A}) = 1 - P(A)$.
- $P(\overline{B}) = 1 - P(B)$.
None of these match $1 - [P(A) + P(B)]$ directly unless $P(A) + P(B) = 1$, which is not necessarily stated.
**Final conclusion:**
$P(\overline{A} \cap \overline{B}) = 1 - P(A) - P(B)$, which is not one of the options 1, 2, 3, or 4 unless further assumptions are made.
So the answer is that $P(\overline{A} \cap \overline{B})$ is not equal to any of the four options provided unless $P(A)$ or $P(B)$ are zero or together sum to 1.