The coin toss and the number cube roll are independent events.
This is because the result of the coin toss does
not affect the result of the number cube roll.
To find the probability of two independent events, we first find the probability of each event, then we multiply the probabilities.
Since there is only one way to get heads when tossing a coin and there are 2 possible outcomes, tossing a heads or tails, the probability of getting heads is 1/2.
Since there is only one way to roll 5 on a number cube, there
is 1 favorable outcome but six possible outcomes.
So the probability of rolling a 5 is 1/6.
Now multiply.
So we have 1/2 · 1/6 which is 1/12.