William has a pair of identical number cubes. the faces of each cube are numbered 1 through 6. william will roll the cubes one time. what is the probability that the numbers showing face-up after the roll will have a sum of 9?
a.1/18b.1/9c.3/4d.8/9

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Аноним Аноним · Answer 1 · 2017-02-27T10:40:09+01:00

The chances will be : 3 and 6 and 4 and 5
The probability of getting a sum of 9 would be 2/9

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virtuematane virtuematane · Answer 2 · 2019-03-13T05:29:57+01:00

Hence, the probability that the numbers showing face-up after the roll will have a sum of 9 is:

1/9

William has a pair of identical number cubes. the faces of each cube are numbered 1 through 6.

Now when he rolls two cubes together the possible outcomes are:

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

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

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

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

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

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

Now, the outcomes having sum 9 is:

(3,6) (6,3) (5,4) (4,5)

Hence total outcomes=36

Number of outcomes having sum 9 ( Number of favorable outcomes)=4

Hence,

Probability( sum is 9)=Number of favorable outcomes/Total outcomes.

= 4/36=1/9

Hence, the answer is:

1/9