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# Conditional Probability - S1 watch

1. how do you find the intersection of two probabilities.

http://www.mei.org.uk/files/papers/s106ja_p3r112.pdf
8 (iv)
2. P( 3 jam) is a subset of P(all 3 the same) so it is simply P(all 3 jam).
3. No, at this point, you are working in the space that all 3 are the same, the the probability is higher than just P(all 3 jam).

Using the definition of classical probability, P(what you want)=P(specific event)/P(whole event). In this case it is P(all 3 jam given all 3 same)=P(all 3 jam)/P(all 3 same), so your answer for (iv) is your answer for (i) divided by your answer for (ii).

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