Re: Monty at it again
Hey Mykey , you're right ...the total sample space should be 74 .
Your second solution is correct and the first solution is flawed .
For P(AB) we said that the total sample space is 80 so that the probability is 8/80 but this is wrong . The 80 elements in our sample space includes multiplicities of equal prizes .
There are clearly 10 choices for the first prize , but there is not always 8 choices for the second . If the first one belongs to c , then there are 7 choices for the second draw .
There are 8 choices for the second prize precisely 40% of the time . There are 7 choices for the second prize 60% of the time .
10*8*0.4 + 10*7*0.6 = 74 .
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