Kevin has two bags, each containing four discs.
Bag 1 contains three discs labelled two and one disc labelled one.
Bag 2 contains two discs labelled three, one disc labelled one and one disc
labelled two.
Bag 1
Bag 2
(2)
(3)
(2)
(1)
(2)
(3)
(2)
Kevin chooses a disc at random from bag 1.
If the disc is labelled 1, he puts the disc in bag 2.
If the disc is labelled 2, he does not put the disc in bag 2.
Kevin then chooses a disc at random from bag 2.
Kevin adds together the numbers from the two discs he selected to give his
score.
Find the probability of Kevin scoring 4