A single fair is tossed. find the probability of rolling a number grater than 4

Probability of the outcome you're looking for =

(number of ways your outcome can happen)

divided by

(total number of possible outcomes).

Total number of possible outcomes when a single fair is tossed = 6.

The outcomes you're looking for: 5 or 6. (two of them).

Probability = 2 / 6 = 1/3 = 33-1/3 %