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Old 08-16-2007   #1
jessie0420
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Default what is the probability of getting a 7 or 11 on two dice. %?

what is the probability of getting a 7 or 11 on two dice. %?
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Old 08-16-2007   #2
Shura
 
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Default Probability of getting a 7 or 11 with two dice.

Well,

The number of combinations of two dice are 6x6=36.

There are 6 ways of getting 7

(6, 1)(1, 6)(5, 2)(2, 5)(4, 3)(3, 4).

So the probability of getting a seven is 6/36 or 1/6 or 16.67% to 2 decimal places. In fact 7 is the most common total of two dice, but even then it only occurs just under 17% of the time.

There are 2 ways of getting 11

(6, 5) and (5, 6)

So the probability of getting 11 is 2/36 or 1/18 or 5.56% to 2 decimal places.

So the probability of getting 7 or 11 is (6+2)/36. The 6 ways of getting 7 plus the two ways of getting 11 out of 36 the number of total combinations of two dice.

This simplifies to 8/36 = 2/9 or 22.22% to decimal places. But probabilities are usually written as a decimal with 1 being 100% certain.

So I would write.

P(of getting a 7 or 11) = 0.22 (to 2 decimal places)

-- Shura
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