If you can get an answer to any question, what would you ask? You toss a fair coin 4 times. What is the probability that (round to 4 decimal places) a) you get all Heads? b) you get at least one Tail?

Answers:

a) 0.0625

b) 0.9375

Work Shown:

The probability of landing on heads is 1/2 = 0.5 since both sides are equally likely to land on. Getting 4 heads in a row is (1/2)^4 = (0.5)^4 = 0.0625

The event of getting at least one tail is the complement of getting all four heads. This is because you either get all four heads or you get at least one tail. One or the other must happen. We subtract the result we got from 1 to get 1-0.0625 = 0.9375

You can think of it like this

P(getting all four heads) + P(getting at least one tail) = 1

The phrasing "at least one tail" means "one tail or more".

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