Rolling two dice is an example of independent events. It means that knowing the result of one die does not influence what you expect from the other.
When this is the case, the probability of the compound event is the product of the two probabilities.
Each die shows an odd number with probability 3/6=1/2, because there are three odd numbers (1, 3 and 5) out of the six possible numbers the die will show (1, 2, 3, 4, 5, 6).
So, if you multiply the probabilities of each die showing an odd number, you'll get the probability of the compound event.
