AS Level Mathematics Paper 5 · Probability & Statistics 1 practice papers
50 marks · 1h 15m. Each generated paper follows the 9709 Paper 5 · Probability & Statistics 1 format, with the same number and style of questions as the real exam, and comes with a Cambridge-style mark scheme.
Sample Paper 5 · Probability & Statistics 1 questions
Question 1Structured · 7 marksA* challenge
The lifetimes of a type of battery are normally distributed with mean 230 hours and standard deviation 19 hours.
(a)
Find the lifetime exceeded by 20% of batteries.
[3]
(b)
8 batteries are chosen at random. Find the probability that exactly 6 of them have lifetimes more than 235 hours.
[4]
Show answers and mark scheme
Part
Answer and marking points
Marks
(a)
246 hours
z = 0.842 B1 μ + zσ M1 246 A1
3
(b)
0.0395
p = 0.3962 B1 binomial with this p M1 28 × p6(1 − p)2M1 0.0395 A1
4
Question 2Structured · 7 marksA* challenge
Bag X contains 5 red and 2 blue discs. Bag Y contains 6 red and 4 blue discs. A biased coin, with P(head) = 0.4, is thrown. If it shows a head, a disc is taken at random from bag X; otherwise a disc is taken at random from bag Y.
(a)
Find the probability that the disc is red.
[2]
(b)
Given that the disc is red, find the probability that it was taken from bag X.
[3]
(c)
Determine whether the events "the coin shows a head" and "the disc is red" are independent. Justify your answer.
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Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in