SOLUTION: Two dice are rolled. Find the probability of getting the following. 2) a sum of 6 or 7 or 8 b) doubles or a sum of 4 or 6 c) a sum greater than 9 or less than 4, Please help me

Algebra ->  Probability-and-statistics -> SOLUTION: Two dice are rolled. Find the probability of getting the following. 2) a sum of 6 or 7 or 8 b) doubles or a sum of 4 or 6 c) a sum greater than 9 or less than 4, Please help me      Log On


   



Question 1097304: Two dice are rolled. Find the probability of getting the following.
2) a sum of 6 or 7 or 8 b) doubles or a sum of 4 or 6 c) a sum greater than 9 or less than 4,
Please help me answer this.

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
Probability of a 6 is 5/36; a 7 is 6/36, and 8 is 5/36 (symmetric)
That is 16/36 or 4/9.
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doubles is 6*(1/36)=1/6
sum of 4 or 6 is 3/36+5/36=8/36
Two of those 8 are doubles and have already been counted, so the sum is 14/36-2/36=12/36 or 1/3.
Of the 36 outcomes, (1,1), (2,2), (3,3), (4,4), (5,5), (6,6), (3,1), (1,3), (1, 5), (2, 4), (4, 2), (5, 1)
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Sum greater than 9 is 10, 11, 12 or 3/36+2/36+1/36, or 6/36
Less than 4 is 3 or 2 which is 2/36+1/36 or 3/36.
The answer is their sum or 9/36 or 1/4.
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2/12 have 1/36 probability
3/11 have 2/36
4/10 have 3/36
5/9 have 4/36
6/8 have 5/36
7 has 6/36