Sum of 8 equal to 5/36 shown here.
At least one 4 means one of three scenarios:
(4, not 4) = 1/6 * 5/6 = 5/36
(not 4, 4) = 5/6 * 1/6 = 5/36
(4, 4) = 1/6 * 1/6 = 1/36
The phrase "or", means we add both probabilities (sum of 8) and (at least one 4):
5/36 + (5/36 + 5/36 + 1/36)
16/36
Simplify...