On a die, there are only 6 faces, numbered 1 to 6.
The probability of rolling a 6 is:
[tex]P(6)\text{ = }\frac{1}{6}[/tex]
This is because there is only one face that has a 6 on it.
The probability of rolling 7 is 0. This is because there is no face with 7 on it.
The probability of rolling a 6 or 7 is the sum of the probabilities of rolling a 6 and a 7, that is:
[tex]P(6\text{ or 7) = }\frac{1}{6}+\text{ 0 = }\frac{1}{6}[/tex]
