Answer:
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The answer would be A because each x only has one y. Hope that makes sense!
Since the dice are fair and the rolling are independent, each single outcome has probability 1/15. Every time we choose

We have
and
, because the dice are fair.
Now we use the assumption of independence to claim that

Now, we simply have to count in how many ways we can obtain every possible outcome for the sum. Consider the attached table: we can see that we can obtain:
- 2 in a unique way (1+1)
- 3 in two possible ways (1+2, 2+1)
- 4 in three possible ways
- 5 in three possible ways
- 6 in three possible ways
- 7 in two possible ways
- 8 in a unique way
This implies that the probabilities of the outcomes of
are the number of possible ways divided by 15: we can obtain 2 and 8 with probability 1/15, 3 and 7 with probability 2/15, and 4, 5 and 6 with probabilities 3/15=1/5
For the first blank where it asks for the perimeter, the perimeter is all the outside sides of a shape added up. So, 6 + 1 + 2 + 4 + 4 + 5 = 22.
For the second blank, you just multiply the entire perimeter by 5, so, 22 times 5=110.
For the third blank, it is basically the same as the previous question. The answer is 5.
For the fourth blank, it is the same perimeter as the first blank, but instead of centimeters, it is in k. So, 22k.
Hope this helped! :)