The probability that Luis will pass his statistics test is 0.33 Find the probability that he will fail his statistics test?

Since Luis can only pass or fail his test, and we know that the probability of all possible outcomes is 1, we therefore see that P(Pass) + P(Fail) = 1

*where P(X) = the probability of event X*

So if P(Pass) = .33;

then P(Fail) = 1 - P(Pass)

= 1 - .33

= .66 (or 66% chance that Luis will fail)