(a)[1]
Find the probability that the first score of $3$ occurs on the $8$th spin.
(b)[2]
Find the probability that fewer than $6$ spins are needed before a score of $3$ is obtained for the first time.
Mathematics 9709 · AS & A Level · Discrete random variables
Discrete random variables — practice question
A fair spinner with $5$ sides labelled $1, 2, 3, 4, 5$ is spun many times. Each spin gives the score shown by the side where the spinner stops.
Worked solution & mark scheme
This 3-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Accurate working of $\left(\frac{4}{5}\right)^7 \times \frac{1}{5}$, or an equivalent method, that reaches the final value” …
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