QuestionLet be two independent events of a sample space, where , . Then 0.8 0.2 0.76 0.18 None of these
Studdy Solution
STEP 1
What is this asking? What's the probability of *not* A happening *or* B happening, if A and B are independent? Watch out! Don't mix up "and" and "or," and remember how independence works!
STEP 2
1. Find P(B)
2. Find P(not A)
3. Apply the formula for P(not A or B)
STEP 3
We're given , which means the probability of B *not* happening is **0.6**.
Since B either happens or it doesn't, the probabilities must add to **one**!
So, .
STEP 4
Let's **calculate** : So, the probability of B happening is **0.4**!
STEP 5
We're given .
Similar to what we did before, since A either happens or it doesn't, we know .
STEP 6
Let's **calculate** : So, the probability of A *not* happening is **0.6**!
STEP 7
Since A and B are independent, we can use the formula: , where .
This formula tells us the probability of *not* A happening *or* B happening (or both!). The last term accounts for the overlap, so we don't double-count when both events happen.
STEP 8
First, let's **calculate** the probability of both *not* A and B happening:
STEP 9
Now, let's **plug** everything into our formula:
STEP 10
Finally, let's **calculate** the result:
STEP 11
The probability of *not* A happening *or* B happening is **0.76**!
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