What is the probability of getting at least two heads when flipping three fair coins?

• A. 1/4
• B. 5/8
• C. 3/8
• D. 1/2

Answer: (D)

When you flip three fair coins, every possible outcome is equally likely, and there are 2^3 = 8 outcomes in total. “At least two heads” means either exactly two heads or exactly three heads. There are 3 ways to get exactly two heads (which two coins show heads) and 1 way to get all three heads, for a total of 4 favorable outcomes. So the probability is 4 out of 8, which simplifies to 1/2.

Another way to see it is to subtract the chance of getting fewer than two heads (0 or 1 head) from 1. There is 1 way to get zero heads and 3 ways to get one head, totaling 4 unfavorable outcomes, again giving 4/8 = 1/2. So the probability is 1/2 (50%).