Final answer:
The probability of the metal ball landing on green or red is 10/19, while the probability of it not landing on green is 18/19.
Step-by-step explanation:
a. The probability of the metal ball landing on green or red is the sum of the individual probabilities. There are two green slots out of a total of 38 slots, so the probability of landing on green is 2/38. There are 18 red slots out of a total of 38 slots, so the probability of landing on red is 18/38. Therefore, the probability of landing on green or red is (2/38) + (18/38) = 20/38, which can be simplified to 10/19 or approximately 0.526.
b. The probability of the metal ball not landing on green can be calculated by subtracting the probability of landing on green from 1. The probability of landing on green is 2/38, so the probability of not landing on green is 1 - (2/38) = 36/38, which can be simplified to 18/19 or approximately 0.947.