Probability: Outcome A OR Outcome B Means Add Probabilities
In an exhibit at the San Diego Zoo, there are 200 crocodiles, 250 owls, 150 parrots, and
400 fish. What is the probability that a randomly chosen animal from the exhibit is a bird?
Correct.
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The total number of animals is
>$$\text{Total} = 200 + 250 + 150 + 400 = 1{,}000$$.
There are two types of birds: owls and parrots. Calculate the probability for each of the two types.
* Owls are 250 out of the 1,000 animals, so the probability is $$\frac{250}{1{,}000}$$.
* Parrots are 150 out of 1,000, so the probability is $$\frac{150}{1{,}000}$$.
Finally, add the probabilities to find the probability of picking a bird:
>$$\text{Probability} = \frac{250}{1{,}000} + \frac{150}{1{,}000} = \frac{400}{1{,}000} = \frac{4}{10} = 0.4$$.
Incorrect.
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Incorrect.
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Incorrect.
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Incorrect.
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0.0375
0.16
0.3625
0.4
0.6
