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2.3 Probability

2.3 Probability

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Question 145

A survey of 120 software developers was conducted to determine which programming languages they used for a specific project: Python (PPP), Java (JJJ), and C++ (CCC). The results were as follows:

  • 54 used Python
  • 48 used Java
  • 42 used C++
  • 18 used Python and Java
  • 20 used Java and C++
  • 14 used Python and C++
  • 6 used all three languages
a.

Represent this information in a Venn diagram.

[4]
b.

A developer is chosen at random from the survey group.

Calculate the probability that the developer used Java but did not use Python or C++.

[1]
c.

Find the probability that the developer used Java or C++ or both.

[2]
d.

Given that the developer used Java or C++ or both,

calculate the probability that the developer did not use Python.

[3]
e.

Determine whether the events 'using Python' and 'using Java' are statistically independent. Justify your conclusion.

[3]
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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