When you roll a six-sided number cube you can get the next set of possible results:
![\lbrace1,2,3,4,5,6\rbrace](https://img.qammunity.org/2023/formulas/mathematics/college/axi7whondxcxpddmmvymwk1rt8n0c6fpme.png)
You have a total of 6 possible results.
From the set of possible results you get the set of presults that are 1 or 6:
![\lbrace1,6\rbrace](https://img.qammunity.org/2023/formulas/mathematics/college/m28hbbxn1icph2y8lh0qx8lpeb4g4rygxo.png)
You have 2 results that are 1 or 6
The probability of rolling (1 or 6) is: The number of results that are 1 or 6 divided in the total number of possible results:
![P(1or6)=(2)/(6)=(1)/(3)](https://img.qammunity.org/2023/formulas/mathematics/college/i2ehwuq3h8g24nof5x1mdr1r1ztzengwul.png)
Then, the probability of rolling (1 or 6) is 1/3