If a pair of dice (one red; the other blue) are rolled,

Question

Find the probability of landing on at least one odd number

Answer 1

The sample space has 36 equiprobable outcomes. You can enumerate the successful outcomes and divide by 36.

Here's another approach:
Success of at least one odd number means that a failure is when both are even.

Probability of a failure is
(1/2)*(1/2)=1/4, we gather that the probability of success is (1-1/4)=3/4, since if it's not a failure, it must be a success.