Answer:
Choice C: 
Step-by-step explanation:
To find your slope do:


that's how you get 1/2
4 is just the y-int.
A+30 = 60
a = 30
a + 2b = 60
30+2b = 60
2b = 30
b = 15
5b - 5c = 60
5(15) - 5c = 60
5c = 15
c = 3
10c + d = 60
10(3) + d = 60
30 + d = 60
d = 30
2d + 6e = 180 - 60
2(30) + 6e = 120
6e = 60
e = 10
4f + 4e = 120
4f + 4(10) = 120
4f = 80
f = 20
To find the probability of both of these occurring, you will multiply the probability of choosing a blue marble by the probability of choosing a purple marble (with no replacement after the first one).
Probability of choosing a blue marble: 17/120
Probability of choosing a purple marble: 18/119
17/120 x 18/119 = 3/140
You will have a 3/140 chance of both of these occurring.