Three unbiased coins are tossed. What is the probability of getting at least 2 heads?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → \(\frac{1}{2}\)
Three coins give \(2^{3}=8\) equally likely outcomes. “At least 2 heads” means 2 heads or 3 heads.
Favourable outcomes, listed in full: HHT, HTH, THH (2 heads) and HHH (3 heads), that is, 4 of the 8
Probability = favourable outcomes divided by all outcomes \(\displaystyle =\frac{4}{8}=\frac{1}{2}\)