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2.3 Probability

2.3 Probability

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Question 135

A marine biology study classifies specimens by three characteristics: Bioluminescence (BBB), High-pressure tolerance (HHH), and Toxicity (TTT). These are represented in a Venn diagram where BBB and TTT are mutually exclusive, while HHH overlaps with both BBB and TTT. The associated probabilities for a randomly selected organism are:

  • The probability of possessing only Bioluminescence is 0.28.
  • The probability of possessing both Bioluminescence and High-pressure tolerance is 0.12.
  • The probability of possessing only High-pressure tolerance is 0.20.
  • The probability of possessing both High-pressure tolerance and Toxicity is 0.15.
  • The probability of possessing only Toxicity is 0.14.
  • The probability of possessing none of these characteristics is 0.11.

Find

a.

P(H′)P(H')P(H′)

[2]
b.

P(B∪T)P(B \cup T)P(B∪T)

[2]
c.

P(B∣H′)P(B | H')P(B∣H′)

[2]
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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