Expected valuehardFree question
Expected value Numerical Reasoning Question
| Prize | Probability |
|---|---|
| £0 | 40% |
| £5 | 35% |
| £25 | 20% |
| £40 | 5% |
A raffle ticket pays the prizes shown with the stated probabilities. What is the expected value of one ticket?
Show worked solution
Expected value = Σ(outcome × its probability). The correct answer is £8.75. Traps to avoid: £5.00 comes from the "single best term" error; £18.25 comes from the "misaligned probs" error; £70.00 comes from the "summed values" error; £17.50 comes from the "unweighted mean" error.
The wrong answers here have names
1034 more questions, every topic and the full mocks are in premium.Unlock
Try similar numerical reasoning questions
Of 88 people, 53 like tea, 43 like coffee, 14 like both. How many like neither?Venn diagramsOne commuter is chosen at random. What is the probability they take the Train?Probability from a tableThe probability of an event is 3/8. What is the probability it does NOT happen?Complement ruleUsing the chart, how much CO2 from a 3.6-mile car journey then a 15.0-mile train journey?Weighted sum