A regular die has 3 odd numbers (1, 3, and 5) and 3 even numbers (2, 4, and 6). The question asks for the probability that an odd number will not be rolled. This is the same as asking the probability of an even number being rolled. Since we have 6 numbers in our data set and 3 are even, we can deduce that 1/2 of them are even and the probability of an even number being rolled is 1/2.
