# Random Variables and Discrete Probability Distribution

X       6        8       10      12   14
P(X=x)  0.15    0.3     0.35    0.1   0.1


What is the probability that fewer than 8 or more than 12 use the lab in a given day?

Am I correct to say that I must just add 0.15 of X = 6 and 0.1 of X = 14?

$$P((X<8) \cup (X>12)) = P(X<8) + P(X>12) - P((X<8) \cap (X>12))$$
with the last term in the sum being $0$ because the event has zero probability.