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2.3.2 Conditional probability (A-level only)

2.3.2 Conditional probability (A-level only)

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Question 125

The Human Resources director of a company is investigating the graduate status and salaries of its employees.

The event G G\,G is defined as the employee is a graduate.

The event H H\,H is defined as the employee earns at least £40 000 \pounds 40\,000\,£40000 a year.

For an employee chosen at random,

P(G∩H)=0.26P(G \cap H) = 0.26P(G∩H)=0.26, P(G∩H′)=0.19P(G \cap H') = 0.19P(G∩H′)=0.19, P(G′∩H)=0.11P(G' \cap H) = 0.11P(G′∩H)=0.11, P(G′∩H′)=0.44P(G' \cap H') = 0.44P(G′∩H′)=0.44

a(i).

Find P(G)P(G)P(G).

[1]
a(ii).

Find P[(G∩H)′]P\left[(G \cap H)'\right]P[(G∩H)′].

[2]
a(iii).

Find P(H∣G′)P(H \mid G')P(H∣G′).

[2]
b.

Determine whether the events G G\,G and H H\,H are independent. Fully justify your answer.

[2]
Markscheme

2.3.2 Conditional probability (A-level only) Questions

  1. A Level
  2. /Maths
  3. /2.3.2 Conditional probability (A-level only)

164 exam-style questions on AQA A Level Maths 2.3.2 Conditional probability (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

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