You can put this solution on YOUR website! There are 6 sides to a standard number cube (ie a die). There is one way to get what you want (rolling a 5) and there are 5 ways to get what you don't want (not rolling a 5, so rolling a 1,2,3,4, or 6)
So the odds in favor are....
Number of ways of getting what you want: Number of ways of getting what you don't want
1:5
The final answer is 1:5 (this is read aloud as "1 to 5")