(a)[3]
Construct the probability distribution table for $X$.
(b)[3]
Find $\mathrm{Var}(X)$.
(c)[2]
The red spinner, with sides numbered 1, 2, 3, 4, is spun repeatedly. Find the probability that it lands on 4 for the first time before the 8th spin.
Mathematics 9709 · AS & A Level · Discrete random variables
Discrete random variables — practice question
A fair red spinner has 4 sides labelled 1, 2, 3, 4. A fair blue spinner has 4 sides labelled 0, 1, 2, 3. When a spinner is spun, the score is the number shown on the side where it comes to rest. Both spinners are spun at the same time. The random variable $X$ represents the larger of the two scores obtained. If the two scores are the same, then $X$ takes the value 0.