[tex]\frac{1}{6}\:or\:(0.1667)[/tex]
1) Since you are taking a multiple-choice, each item has 6 choices. And the question does not mention the number of questions. So, let's assume it's one single question with 6 choices.
Something like:
a)
b)
c)
d)
e)
f)
2) So, our sample space is 6 the number of total outcomes.
3) There is only one choice, so the favorable event is 1
4) So now, we can write the probability as the ratio between the favorable events and the total outcomes:
[tex]P=\frac{1}{6}[/tex]
