Skip to content

GCSE & IGCSE maths practice

Probability questions and answers

Probability = number of ways it can happen ÷ total number of equally likely outcomes. Probabilities go from 0 (impossible) to 1 (certain), and all the outcomes add to 1, so P(not A)=1−P(A)P(\text{not } A) = 1 - P(A). Expected number of times =P×= P \times number of trials. Give answers as fractions, decimals or percentages.

8 questions · Foundation tier · Every answer is checked as you type it, with a full worked solution. Updated .

Where probability comes up

GCSE (AQA, Edexcel, OCR)Foundation and Higher: probabilities of single events, outcomes that sum to 1, expected outcomes, relative frequency and sample spaces.
Cambridge IGCSE (0580)Core and Extended: probability of events, P(not A) = 1 − P(A), relative and expected frequencies, and sample space diagrams.

The method

  1. P(event) = favourable outcomes ÷ total outcomes.
  2. Probabilities of all outcomes add to 1.
  3. Expected number = probability × trials.
  4. Relative frequency = times it happened ÷ trials.

Probability questions

Try each one before looking at the hint. If you're stuck, the AI tutor can talk you through it step by step.

Warm-up

Question 1Warm-upFoundation

A bag has 3 red, 5 blue and 2 green counters. One is taken at random. Find P(blue).

Question 2Warm-upFoundation

Using the same bag, find P(not red).

Exam-style

Question 3Exam-styleFoundation

A spinner lands on red (0.2), blue (0.35), green (xx) or yellow (0.15). Find xx.

Question 4Exam-styleFoundation

The probability of winning a game is 0.15. You play 60 times. How many times would you expect to win?

Question 5Exam-styleFoundation

A coin is flipped 50 times and lands on heads 37 times. What is the relative frequency of heads?

Question 6Exam-styleFoundation

Two fair dice are rolled and the scores added. Find the probability of a total of 7.

Challenge

Question 7ChallengeFoundation

A spinner has P(A) =2x= 2x, P(B) =3x= 3x and P(C) =0.5= 0.5. Find P(A).

Question 8ChallengeFoundation

A bag has 12 counters and P(red) =13= \tfrac{1}{3}. How many red counters must be added to make P(red) =12= \tfrac{1}{2}?

Common mistakes

  • Giving a probability greater than 1.
  • Writing probability as a ratio (1 : 3) instead of a fraction.
  • Forgetting some outcomes when listing a sample space.

Stuck on one of these?

The TutorAura AI tutor works through it with you step by step, with the reason for each step, then gives you one like it to try. It checks your working too.

Try the AI tutor free

More maths questions

GCSE maths mock papers · IGCSE maths mock papers · All maths topics

Sources

The questions are our own. The “where it comes up” notes are from each board's published specification, checked on 26 October 2026:

Practise maths with your own AI tutor

Questions at your level, help when you're stuck, and a plan for your exams. Free for 3 days, no card needed.

Start free trial