Question

We flip a fair coin 10 times. What is the probability that we get heads in exactly 8 of the 10 flips?

Answer 1

There are
`2^(10)` possible outcomes when flipping 10 coins. Of those
`{10 \choose 8}` have exactly 8 heads. So the probability is

`p = \frac{ {10 \choose 8} }{ 2^(10) } = (10(9)/2)/(2^(10))=(45)/(1024)`

Answer: 45/1024