what are the odds in favor of getting at least one head in three successive flips of a coin?

Question

I need to know the formula on this. I have 1/6 over 1- 1/6. But I can't figure out how to do the math. Am I right?

Answer 1

the probability of getting at least one head is = 1-prob(three tails)=1-1/8=7/8

so the odds are 7:1 to get at least one head.

Answer 2

It' is the other way around if you multiplt your runner.