Answer
$P(not~G)=\frac{36}{38}=\frac{18}{19}\approx0.947$
Work Step by Step
The sample space S = "38 slots". So, N(S) = 38.
Let R be the event "red slot" (odd-numbered). So, $N(R) = 18$.
Let B be the event "black slot" (even-numbered). So, $N(B) = 18$.
Let G be the event "0, 00" . So, $N(G)=2$.
The event "the metal ball does not land on green" is the complement of "the metal ball lands on green". So, using the Complement Rule (page 275):
$P(not~G) = 1-P(G)=1-\frac{N(G)}{N(S)}=1-\frac{2}{38}=\frac{38}{38}-\frac{2}{38}=\frac{36}{38}=\frac{18}{19}\approx0.947$
