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2.3 Probability

2.3 Probability

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Question 142

In a study of genetically modified crop cultures, let R R\,R be the event that a culture exhibits rapid growth and S S\,S be the event that it shows stress resistance. Historical data suggests that:

P(R∩S)=0.12 P(R \cap S) = 0.12 P(R∩S)=0.12 P(R′∩S′)=0.28 P(R' \cap S') = 0.28 P(R′∩S′)=0.28 P(S)=2P(R) P(S) = 2P(R) P(S)=2P(R)
a.

Determine P(R)P(R)P(R).

[4]
b.

Find the probability that a culture shows stress resistance, given that it exhibits rapid growth.

[2]
c.

Determine, with a calculation, whether R R\,R and S S\,S are independent events.

[1]
Markscheme

2.3 Probability Questions

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

200 exam-style questions on OCR A Level Maths 2.3 Probability, covering 2.3.1 Mutually exclusive and independent events, 2.3.2 Diagrams to assist probability calculations, 2.3.3 Conditional probability (A-level only), 2.3.4 Conditional probability from first principles (A-level only), and 2.3.5 Modelling with probability. Each one has a worked solution and a mark scheme showing where the marks go.

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