Question

The probability of winning a game is 20% if you play 20 times how many times should you excpect to win?

Answer 1

you should win 40 times

Answer 2

Given that the probability of winning a game is 20%. The number of games won out of 20 follows binomial probability distribution.

The probability distribution/mass function is

`P(X=x)=C(n,x)p^x(1-p)^(n-x),x=0,1,2,3,...,n`. Here
`n=20,p=0.2`

The expected value of X is

`E(X)=np=20*0.2=4`