1. Problem: A fair coin is tossed 3 times. Find the probability that at least one head appears. 2. Formula: The probability of at least one head is the complement of the probability of no heads (all tails). 3. Calculation: - Total outcomes when tossing a coin 3 times: $2^3 = 8$ - Probability of all tails (no heads): $\frac{1}{8}$ - Probability of at least one head: $1 - \frac{1}{8} = \frac{7}{8}$ 4. Explanation: Since the only way to have no heads is all tails, subtracting that probability from 1 gives the probability of at least one head. Final answer: The probability that at least one head appears is $\boxed{\frac{7}{8}}$.