A red spinner has four sides numbered 1, 2, 3, 4. Each time the spinner is spun, the score is the number on the side where it lands. The random variable $X$ represents this score, and the probability distribution table for $X$ is shown.
(a)[1]
Show that $p = 0.12$.
(b)[3]
A fair blue spinner and a fair green spinner each have four sides numbered 1, 2, 3, 4. The red, blue and green spinners are all spun together. Find the probability that the sum of the three scores is 4 or less.
(c)[5]
Find the probability that the product of the three scores is $4$ or less given that $X$ is odd.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Forms the correct equation from the total probability $0.28+6p=1$ and then finds $p=0.12$.” …