Not less than 5 would be a 5 or a 6

So that's 2 out of 6

2/6

Probability 1/3

:-

P ( not less than 5 ) = 1 - P ( more than 5 )

P ( not less than 5 ) = 1 - 1/6 = 5/6

Your options for "not less than 5" are rolling a 5 or a 6.

So your question becomes, find the probability of obtaining a 5 or a 6.

What would be your answer to that?

Am I going to take your exam too? Rolling it once? 2/6.  You REALLY need help with that?  Wow, don't sleep in class.