Pearson Edexcel International GCSE in Mathematics (Specification A) · 4MA1 · Free · no account needed
Probability Basics — exam questions
9 original Incandio exam-style questions on Probability Basics, 20 marks, about 23 minutes of writing. Each one carries the command word, the tariff and the specification statement it assesses, exactly as a paper presents them. This is an original Incandio practice question, written to reflect the structure and demands of the qualification. It is not an official Pearson Edexcel past-paper question.
This is the practice set for Probability Basics — the module that teaches it. Read the module first if the idea is new; come here when you want to find out whether you can turn it into marks. Completely free, no account needed to read.
What these questions ask of you
4 command words run through this set, and on Pearson Edexcel International GCSE Mathematics A each one means something precise. Answering the wrong command is the commonest way a candidate who understands the module still loses the mark.
- Write down (1–2 marks)
- a value that needs no working — read off, recalled or stated
- Work out (1–5 marks)
- a calculated result, with the working that produced it
- Give a reason for your answer (1–3 marks)
- the geometric or statistical reason NAMED precisely — the mark scheme demands the terminology Misread as: describing what you did instead of naming the property that justifies it
- Explain why (1–2 marks)
- one short justification — mathematics almost never asks for extended explanation
Assessed on Paper 1 and Paper 2.
Where these sit in the specification
Pearson Edexcel International GCSE Mathematics A (4MA1) — statement 6.3. Incandio is aligned to this specification; it is not published by, endorsed by or affiliated with Pearson, and it reproduces none of Pearson's wording.
The 9 questions
Answer them on paper, then open the module's exam practice to have them marked. The mark scheme, the accepted and rejected answers and the annotated model answer are in Incandio and are not printed here — an answer beside its question is not practice.
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(1)Write down
A fair six-sided dice is rolled once. Write down the probability of scoring a 4.
probability of scoring a 4 = ............................
(Total for Question 1 = 1 mark)
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(2)Work out
A bag contains 7 red counters, 5 blue counters and 8 green counters. One counter is taken at random. Work out the probability that it is not blue.
(Total for Question 2 = 2 marks)
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(1)Work out
The probability that a train is late on any morning is 0.15. Work out the probability that it is not late on a particular morning.
(Total for Question 3 = 1 mark)
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(2)Work out
Work out the relative frequency of scoring a 2 with the spinner in Table 1.
Table 1 — the results of spinning a five-sided spinner 400 times. Score 1 2 3 4 5 Frequency 63 97 82 71 87 (Total for Question 4 = 2 marks)
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(2)Give a reason for your answer
Decide whether the spinner in Table 1 is likely to be fair, and give a reason for your answer.
Table 1 — the results of spinning a five-sided spinner 400 times. Score 1 2 3 4 5 Frequency 63 97 82 71 87 (Total for Question 5 = 2 marks)
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(3)Work out
The spinner in Table 1 is spun 1000 more times. Work out an estimate for the number of times it will score a 5.
Table 1 — the results of spinning a five-sided spinner 400 times. Score 1 2 3 4 5 Frequency 63 97 82 71 87 (Total for Question 6 = 3 marks)
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(1)Explain why
A student says: "I spun the spinner 20 times and got four 3s, so the probability of a 3 is exactly 0.2." Explain why she is wrong.
(Total for Question 7 = 1 mark)
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(3)Work out
A bag contains only red and yellow counters. The probability of taking a red counter at random is 3/8. There are 15 red counters. Work out how many yellow counters there are.
(Total for Question 8 = 3 marks)
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(5)Work out
A bag contains 5 red counters, 8 blue counters and some green counters. The probability of taking a green counter at random is 0.35. Work out the number of green counters in the bag.
number of green counters = ............................
(Total for Question 9 = 5 marks)
Have them marked, then defend the answer
Practice tells you the mark; teaching it back tells you whether you understand it. On Incandio a topic counts as mastered only once you have taught it and defended it.
- Mark these questions — 9 questions, marked on Incandio against the authored scheme, with the mistake you actually made named.
- Teach it — explain Probability Basics to Ember, an AI pupil who does not have it yet and asks the awkward question.
- Defend it — argue it against Blaise Pascal over three rounds, marked against descriptors you can read first.
Completely free. No subscriptions, no paywalls, no account needed to start.
Back to the module
- Probability Basics — Probability as fair counting: single events, 'not' events, expected frequency and relative frequency — the foundations every tree diagram stands on.
- All of Incandio Mathematics · Incandio Exam Practice