An ordinary dice is rolled what are the odds against and in favour of the event "multiple of Three"?

Answer 1

multiple of three:3 or 6

pr (3or6)=2/6=1/3
pr(not 3or6)=1-1/3=2/3

Answer 2

so the odds against multiple of three = (2/3) : (1/3)
= 2 : 1

the odds in favour of multiples of three = 1 : 2