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2.3 Probability

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Question 35

A media analyst surveys 120 people about which streaming services they use. They can choose from Netflix (NNN), Disney+ (DDD), and Amazon Prime (AAA).

15 people use all three services. 25 people use Netflix and Disney+. 22 people use Disney+ and Amazon Prime. 30 people use Netflix and Amazon Prime. 70 people use Netflix. 50 people use Disney+. 60 people use Amazon Prime.

a.

Draw a Venn diagram for this information.

[3]
b.

One of the people is selected at random. Given they use Amazon Prime, find the probability they do not use Netflix.

[3]
Markscheme

2.3 Probability Questions

  1. A Level
  2. /Maths
  3. /2.3 Probability

200 exam-style questions on OCR (MEI) A Level Maths 2.3 Probability, covering 2.3.1 Calculate the probability of an event, 2.3.2 Complementary events, 2.3.3 Expected frequency of an event, 2.3.4 Diagrams to calculate probabilities, 2.3.5 Mutually exclusive and independent events, 2.3.6 Add probabilities for mutually exclusive events, 2.3.7 Multiply probabilities for independent events, 2.3.8 Mutually exclusive and independent events (notation) (A-level only), 2.3.9 Venn diagrams for probabilities (A-level only), 2.3.10 Conditional probabilities (A-level only), and 2.3.11 Independence via conditional probability (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

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