One ball is selected from 100 at a time, without replacement. Of these balls, r of them are red.(adsbygoogle = window.adsbygoogle || []).push({});

What is the probability that the first ball picked will be red?

The 50th?

The last?

Solution:

I don't understand why it matters which pick it is. I know that "without replacement" changes things quite a bit, but in my mind if the picks are random then that's like arranging them in a random line and having them being picked in that order, in which case the probability that the 50th is red is the same as that of the first or last. So my intuition says r/100 for everything, but none of the previous section in the book has an applicable equation to confirm my intuition. Is my thinking correct?

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# Homework Help: Probability; 100 balls, r are red.

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