(a(i))[1]
Megan chooses one ball at random. Write down the probability that the ball is red or blue.
(a(ii))[1]
Calculate the expected number of times the ball will be red or blue.
(b)[4]
Mick selects 2 of the 12 balls at random, without replacement. Calculate the probability that the two balls are of different colours.
(c)[2]
Find the value of $n$ from this condition.