Probability = (number of possible successes) / (number of total possibilities).
Number of total possibilities:
Each cube can come up in 6 different ways.
Total number of possibilities = 6 x 6 = 36
Possible successes:
There are 2 different ways to roll a 3 . . .
1 . . . 2
or
2 . . . 1
The probability is 3/36 = 1/12 = 0.0833... = (8 and 1/3) percent