Answer: Hello there!
here we have 20 chips, where 4 are blue, 5 are red and 11 green.
Now we want to see if the game is fair or not, to see this, let's see the expected value of the game:
the expected value is defined as E = ∑pₙxₙ
where pₙ is the probability of the event xₙ
Here we have 3 events:
win 1 dollar, where the probability is the number of red chips divided by the total amount of chips 5/20
win 0 dollars, whit a probability of 11/20
loss of 1.25 dollars, with a probability of 4/20
then the expected value is:
E = ($1*5 + $0*11 - $1.25*4)/20 = $0
Then the expected value is 0 dollars, this means that the game is not biased in any direction.
Then, the game is a fair game.