Practice

Probability practice

Practise probability at your own pace. Choose a difficulty, try each question on paper or in your jotter, use hints only when you need a start, then show answers to check your work.

Take quiz Pupil practice hub

Pupil practice

Build your confidence

Choose a difficulty and practice length, write down your working, then reveal answers only when you are ready to check. Hints give a starting point without giving away the answer.

DifficultyPractice length

Practice set

Current set: Mixed. Show your method for each question before checking answers.

1. A card is chosen from cards numbered 1 to 20. What is the probability of choosing a multiple of 4?
Outcome count
Successful cards 5
Total cards 20
2. Which is more likely: an event with probability 0.75 or one with probability 45?
Probability comparison
0 impossible0.5 even chance1 certain
0.75 compared with 4/5
3. A safety system has two independent alarms. Each fails with probability 0.1. Find the probability both fail and decide whether a 2% maximum-failure rule is met.
4. A probability is 0. Which likelihood word best describes it?
Probability scale
0 impossible0.5 even chance1 certain
Probability = 0
5. A bag contains 4 red counters out of 7. One counter is selected and replaced, then a fair coin is tossed. Find P(red and heads). Give a decimal.
Two-stage experiment
Stage Supplied information
Counter 4 red out of 7
Coin 1 head out of 2 equal outcomes
Replacement Yes
6. Which is more likely: an event with probability 0.75 or one with probability 23?
Probability comparison
0 impossible0.5 even chance1 certain
0.75 compared with 2/3
7. A probability is 1. Which likelihood word best describes it?
Probability scale
0 impossible0.5 even chance1 certain
Probability = 1
8. A bag contains 3 red counters out of 6. One counter is selected and replaced, then a fair coin is tossed. Find P(red and heads). Give a decimal.
Two-stage experiment
Stage Supplied information
Counter 3 red out of 6
Coin 1 head out of 2 equal outcomes
Replacement Yes
9. A bag has 3 blue and 2 yellow counters. Two counters are selected without replacement. Find the probability both are blue.
Counter bag
Colour Starting count
Blue 3
Yellow 2
Replacement No
10. A bag has 4 red counters and 4 blue counters. What is the probability of picking a red counter?
Counter bag
Red 4
Blue 4
Total 8

Successful cards	5
Total cards	20

Stage	Supplied information
Counter	4 red out of 7
Coin	1 head out of 2 equal outcomes
Replacement	Yes

Stage	Supplied information
Counter	3 red out of 6
Coin	1 head out of 2 equal outcomes
Replacement	Yes

Colour	Starting count
Blue	3
Yellow	2
Replacement	No

Red	4
Blue	4
Total	8

Practice answers

Check your work when you are ready.