(i)[2]
Determine the probability that the two socks chosen are different colours.
(ii)[3]
The random variable $X$ counts the number of red socks chosen. Complete the probability distribution table for $X$.
(iii)[1]
Find $\text{E}(X)$.
Mathematics 9709 · AS & A Level · Sampling and estimation
Sampling and estimation — practice question
Andy keeps 4 red socks and 8 black socks in his drawer. He chooses 2 socks at random from the drawer.
Worked solution & mark scheme
This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Setting up the probability for different colours with paired probabilities, for example $P(RB)+P(BR)$ or an equivalent approach” …
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