The probability of rolling any one number on a 6 sided die is 1/6
The probability of rolling a 4 is 1/6
The probability of rolling a 5 is 1/6
The probability of rolling a 4 or a 5 is the probability of rolling a 4 plus the probability of rolling a 5:
1/6 + 1/6 = 2/6 = 1/3
The answer is 1/3
