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

Options

A. `3/16`
B. `1/4`
C. `5/16`
D. `7/16`

Answer

C

Explanation

Since each of ht 4 flips has 2 possible outcomes (heads or tails), there are `2^(4)=16` outcomes in the sample space. At least 3 heads means 3 or 4 heads.
`((4),(3))=4` ways to get 3 heads. `((4),(4))=1` way to get 4 heads and `(4+1)/(16)=(5)/(16)`.