Context for question 4
Ebere has a coin which is biased so that the probability of obtaining a head is . She also has two bags containing coloured discs. Bag A contains 5 red discs and 3 blue discs. Bag B contains 4 red discs and 5 green discs.
Ebere tosses her coin. If she obtains a head, she chooses two discs from bag A, at random, one at a time and without replacement. If she obtains a tail, she chooses two discs from bag B, at random, one at a time and without replacement.