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I have a question I have worked out and I would like to check my solution. I am told that 4 fair coins are tossed in succession. I am to find the probability of getting 4 tails given that the first 2 tosses were all tails.

I got $$\frac{1/16}{1/4} = \frac{1}{4}.$$ Is this right?

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    That’s right, though you could get the answer more easily by noticing that what you want is simply the probability that the last two tosses are both tails, which is $\left(\frac12\right)^2=\frac14$.2012-06-07
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    yeah...that's right. I didn't notice that. Thanks.2012-06-07
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    @count: You can answer your own question now that you know the right answer.2012-06-07

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