Flip two fair coins. What is the probability of getting at least one tail?

1. The sample space of two flips holds HH, HT, TH and TT. 2. At least one tail means one tail or two tails, which covers HT, TH and TT. 3. That is three of the four outcomes, so the probability is 3/4. 4. A probability of 1/4 belongs to getting all tails, which is the complement of at least one head. _Source: OpenStax Introductory Business Statistics (CC BY 4.0), Ch 3 "Probability Topics", section 3.2 Independent and Mutually Exclusive Events_