This is a binomial distribution with n=12 and p=0.9 Expected value =np P(X=r)=nCr(1-p)^n-r(p)^r
So P(X=12)=(0.9)^12
For fewer than 10 work out P(X=10)+P(X=11)+P(X=12) and subtract this answer from 1
A certain basketball team has 12 players on the roster. Each player has a 90% chance of showing up to practice, and the event that each player shows up is independent of the events that the other players do.
1. Find the number of players that are expected to attend each practice.
2. Find the probability of all 12 players showing up to practice.
3. Find the probability that fewer than 10 players show up.