The probability will be the number of favorable outcomes over the total number of outcomes.
The number of favorable outcomes will be the numbers greater than 4 (5,6) and the even numbers (2,4,6). So the favorable outcomes are 2,4,5, and 6. That is 4 total.
Getting a number greater than 4 means getting 5 or 6 Getting an even number means getting 2,4 or 6 Hence there are 4 favorable cases out of 6 possible cases, and the probability is 4/6=2/3.