A biased spinner can only land on one of the numbers 1, 2, 3 or 4. The random variable X X\,X represents the number that the spinner lands on after a single spin and P(X=r)=P(X=r+1)P(X = r) = P(X = r + 1)P(X=r)=P(X=r+1) for r=1,3r = 1, 3r=1,3
Given that P(X=1)=0.20P(X = 1) = 0.20P(X=1)=0.20
find the complete probability distribution for XXX.
Mark spins the spinner 20 times. Find the probability that the spinner lands on the number 4 more than 5 times.
The random variable Y=7−2XY = 7 - 2XY=7−2X. Find P(Y+X≥4)P(Y + X \geq 4)P(Y+X≥4)
215 exam-style questions on Edexcel A Level Maths Statistical Distributions, covering 6.1 Probability Distributions, 6.2 The Binomial Distribution, and 6.3 Cumulative Probabilities. Each one has a worked solution and a mark scheme showing where the marks go.