A coin is thrown 4 times. What is the probability of getting at least three heads?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → \(\frac{5}{16}\)
Four tosses have \(2^4=16\) equally likely outcomes. “At least three heads” means three heads or four heads.
Three heads and one tail: the one tail can be any of the 4 tosses, so 4 outcomes
Four heads: 1 outcome (HHHH)
Probability \(=\frac{4+1}{16}=\) \(\frac{5}{16}\)