Mathematics 9709 · AS & A Level · The Poisson distribution
The Poisson distribution — practice question
Each packet of a particular brand of biscuits contains one free plastic robot. The plastic robots come in four colours — red, yellow, blue and green — and each colour is equally likely. Nick purchases some of these biscuit packets.
(i)[1]
Find the probability that the robot in his first packet is green.
(ii)[2]
Find the probability that his first green robot appears when he opens his fifth packet.
(iii)[3]
Nick’s friend Amos is also collecting robots. Find the probability that the first four packets Amos opens each contain a robot of a different colour.
Worked solution & mark scheme
This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Correct probability $\frac{1}{4}$” …