Homework for 9c for Wednesday May 22, 2019.
A bag contains 2 blue balls and 3 green balls.
Pete takes a ball at random from the bag, records its colour and replaces
it.
He does this two more times.
Work
out the probability that, of the three balls Pete takes, exactly two are the
same colour.
(Hint – what is the alternative to
2 being the same colour?)