Answer: 1/18
Step-by-step explanation
There are 6*6 = 36 ways to roll two dice.
Of those, we have two ways to roll a "3"
1+2 = 3
2+1 = 3
Therefore, 2/36 = 1/18 represents the probability of rolling a "3".
1/18 = 0.0556 = 5.56% approximately
The '5's go on forever, but we have to round at some point. That explains the '6' at the very end.