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One Pair
A pair of fair dice is cast. What is the probabiliy that at least one of the numbers falling uppermost is a 1,?
A pair of fair dice is cast. What is the probabiliy that at least one of the numbers falling uppermost is a 1, given that the sum of the numbers falling uppermost is even?
1-2*(5/6)(3/6)
=(36/36)-(30/36)
=6/36
=1/6
What the guys below are FAILING to realize is that the sum of the uppermost numbers must be even. It would only be 11/36 if the sum of the numbers falling uppermost could be even OR odd.
To see this there are 36 possible combinations. 6 x 6.
The possible outcomes in this set are: {(1,1),(1,3),(1,5),(1,1),(3,1),(5,1)}
This is 6/36 = 1/6