Question

an experiment consists of flipping a fair coin 4 times. What is the probability of obtaining at least one head?

Answer 1

`\mathbb P(X\ge1)=1-\mathbb P(X=0)`

The probability of getting 0 heads in 4 tosses (or equivalently, 4 tails) is
`\frac1{2^4}=\frac1{16}`.

So the desired probability is


`1-\frac1{16}=(15)/(16)`