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# S1 discrete random variables Watch

1. In this question

for 0, doesn't that mean the probability that no dogs are chosen so the cats are chosen so 3/7?
2. (Original post by Secret.)
In this question

for 0, doesn't that mean the probability that no dogs are chosen so the cats are chosen so 3/7?
Yes, it means no dogs are chosen.

But two animals are chosen, so it's not 3/7 (which would be correct if just one animal was chosen).
3. (Original post by ghostwalker)
Yes, it means no dogs are chosen.

But two animals are chosen, so it's not 3/7 (which would be correct if just one animal was chosen).

Aah so 3/7 * 2/6?
4. (Original post by Secret.)
Aah so 3/7 * 2/6?
You got it!
5. (Original post by ghostwalker)
You got it!

Thanks!

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