If your choices are the following:
A. 9π
B. l8π
C. 27π
D. 36π
Then the answer would be C. 27π.
2 black marbles:

1 white, 1 black:

1 white, 1 non-black (this means you draw either 2 white, or 1 white and 1 red; we add the events' probabilities because they are disjoint events):
D. You need the data values to figure it out
Answer:
A. 9 in
Step-by-step explanation:
The diameter of the circle is 18 in. The radius is half the diameter of the circle.
d= 18 in
r= 18/2
= 9 in