There are [tex]2^{10}[/tex] possible outcomes when flipping 10 coins. Of those [tex] {10 \choose 8} [/tex] have exactly 8 heads. So the probability is
[tex]p = \dfrac{ {10 \choose 8} }{ 2^{10} } = \dfrac{10(9)/2}{2^{10}}=\dfrac{45}{1024}[/tex]
Answer: 45/1024
