(a)[1]
Find the value of $P(X = 7)$.
(b)[2]
Find $P(3 \leq X \leq 5)$.
Mathematics 9709 · AS & A Level · Discrete random variables
Discrete random variables — practice question
A fair six-sided die with faces numbered 1, 2, 3, 4, 5, 6 is thrown repeatedly. The random variable $X$ represents the number of throws needed before a 6 is obtained.
Worked solution & mark scheme
This 3-mark question has a full step-by-step worked solution and mark scheme. One marking point: “The calculation $\left(\frac{5}{6}\right)^6\left(\frac{1}{6}\right)$ gives $\frac{15625}{279936}$, which is $0.0558$.” …
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