Answer:
C.
Step-by-step explanation:
WE need to convert the given equations into the standard form
(x - a)^2 + (y - b)^2 = r^2 where r = the radius.
x^2 + y^2 + 12x - 20y+ 132 = 0
(x + 6)^2 - 36 + (y - 10)^2 - 100 = -132
(x + 6)^2 + (y - 10)^2 = -132 + 36 + 100 = 4
giving a radius of 2
x^2 + y^2 + 12x - 20y + 55 = 0
will give a right hand side of -55 + 36 + 100 = 81 giving radius 9.
x^2 + y^2 - 12x+ 20y + 127 = 0
- gives right hand side of -127 + 36 + 100 = 9 giving a radius of 3.
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
90 ft.......hope this helps