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Conditional Probability

Conditional Probability

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Question 17

A box contains only blue pens and black pens. There are 8 blue pens and 4 black pens.

Chloe takes at random a pen from the box. She does not put the pen back in the box.

Chloe takes at random a second pen from the box.

a.

Complete the probability tree diagram.

A probability tree diagram for two pens. The first selection has two branches: Blue and Black, each with a dotted line for probability. The second selection has four branches: Blue, Black, Blue, and Black, each with a dotted line for probability.

[2]
b.

Work out the probability that Chloe takes two pens of the same colour.

[2]
Markscheme

Conditional Probability Questions

  1. GCSE
  2. /Maths
  3. /Conditional Probability

28 exam-style questions on AQA GCSE Maths Conditional Probability. Each one has a worked solution and a mark scheme showing where the marks go.

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