The probability scale | Maths | Quizalize & Oak National Academy

Starter quiz

Which letter on the scale of likelihoods represents 'even chance'?
- A
- B
- C ✓
- D
- E
What does the letter A represent on the scale of likelihoods?
- certain
- even chance
- impossible ✓
- likely
- unlikely
Which word describes the likelihood of an outcome that is guaranteed to happen?
- certain ✓
- even chance
- impossible
- likely
- unlikely
Which percentage is equivalent to 0.1?
- 0.001%
- 0.01%
- 0.1%
- 1%
- 10% ✓
Which fraction is equivalent to 50%?
- ${1}\over{2}$ ✓
- ${1}\over{5}$
- ${1}\over{20}$
- ${1}\over{50}$
What is 25% of 2000?
- '500' ✓

The letter E on the scale represents a probability of ______%.
- '100' ✓
Which probabilities are equivalent to an 'even chance'?
- 0.2
- ${1}\over{2}$ ✓
- 0.5 ✓
- 50% ✓
- ${1}\over{5}$
What is the probability of an event that is impossible?
- '0' ✓
Which is the probability that this spinner lands on 'win'?
- 1%
- 47% ✓
- 50%
- 53%
- 99%
A trial has three possible outcomes: {A, B, C}. P(A) = ${1}\over{2}$ . P(B) = ${1}\over{3}$ . P(C) = ${1}\over{6}$ . Which outcome is most likely to happen?
- A ✓
- B
- C
The probability on an outcome is 20%. Approximately how many times could you expect the outcome to occur in 500 trials?
- 20
- 50
- 100 ✓
- 200
- 250

Pupils think that 'likely' from the scale of likelihoods is only equal to a specific probability (e.g. 75%).

All probabilities that are greater than 50% but less than 100% are equivalent to 'likely' on the scale of likelihoods.

Probability - The probability that an event will occur is the proportion of times the event is expected to happen in a suitably large experiment.