Well, if you wanted the answer, it is provided in the picture that you yourself have uploaded. However, if need more clarification on how to find that answer. Here I go.
So, you can ask yourself, how many numbers are on the cube? 6, from 1-6. So there are 6 possible outcomes. Now between the numbers 1, 2, 3, 4, 5, 6, how many are the numbers 2, 3, or 4? There are 3, so it is 3/6, 1/2, 50%, or 0.5.