Well. A die has six sides, right?
Each side has a number, which is:
1, 2, 3, 4, 5, 6
What the question is asking for is the chance of getting an even number. The even numbers are 2,4,6.
So, out of six different possible numbers, three of them are even.
That's a 50% chance of getting an even number, right?
So you're answer is
3/6, which simplifies to 1/2.