9709 P62 - Nov 2013 - Q5
3041
On trains in the morning rush hour, each person is either a student with probability 0.36, or an office worker with probability 0.22, or a shop assistant with probability 0.29 or none of these.
8 people on a morning rush hour train are chosen at random. Find the probability that between 4 and 6 inclusive are office workers.
