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2.3 Probability

2.3 Probability

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Question 12

A distribution center receives electronics from three different suppliers. Supplier X provides 50% of the electronics, Supplier Y provides 30%, and Supplier Z provides 20%.

If an item comes from Supplier X, the probability it is damaged is 4%. If an item comes from Supplier Y, the probability it is damaged is 5%. If an item comes from Supplier Z, the probability it is damaged is 8%.

a.

Draw a tree diagram to show this information.

[3]
b.

An item is selected at random. Find the probability it is damaged.

[2]
c.

Given that the item is damaged, find the probability it was from Supplier Z.

[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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