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Suppose you roll two standard number cubes once. Find the probability. P(7 or even)

1 Answer

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To roll a seven you could have (1,6) (6,1) (2,5) (5,2) (3,4) (4,3)

6 different ways so 6/36 reduces to 1/6 way of getting a 7

For getting an even number as sum, we can have (1,1) or (1.3) or (1,5) or (2,2) or (2,4) or (2,6) or (3,1) or (3,3) or (3,5) or (4,2) or (4,4) or (4,6) or (5,1) or (5,3) or (5,5) or (6,2) or (6,4) or (6,6) 18 ways, probability is 18/36 reduces to ½

So for either one you now have 1/6 + 1/2 = 6+2/12 = 8/12 reduced to 2/3


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