Question

During lunch, all 240 students flipped 3 coins. How many students would you expect to get exactly 1 tails?

Answer 1

`n=240`

The probability of getting exactly 1 tail from three coins is

`\begin{gathered} THH,HTH,HHT \\ \\ p=(3)/(2^3) \\ \\ p=(3)/(8) \end{gathered}`

The expected value will be

`\begin{gathered} E(X)=240*(3)/(8) \\ \\ E(X)=90 \end{gathered}`

The answer is 90 students