When a die is tossed, there are six possible outcomes
The outcomes are the numbers that might show up
The number of outcomes we can have is 1 to 6 and this makes 6 possible outcomes
Now, the number of 5's we have on a die is 1
So what this means is that out of the 6 possible results, 1 can be 5
So the probability is simply the number of times 5 can show up divided by the total number of possible outcomes
Mathematically, this is;