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4MA1/2F Jan 2022, Question 2: Functions as a Mapping

Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 2F (Foundation) · Calculator · 6 marks

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The question, in short

Use the given list of seven numbers to pick out numbers of stated types, then reverse a number machine that multiplies by 5 and adds 3.

Summarised in our own words. Use the official paper for the exact wording and the diagram.

Part (ai) · 1 mark

Choose from the list a number that is a cube.

  1. 1Look for a number that is a cube: 2³ = 8
  2. 28 is in the list

Answer8

Part (aii) · 1 mark

Choose from the list a number that divides 70 exactly.

  1. 1Find a factor of 70: factors are 1, 2, 5, 7, 10, 14, 35, 70
  2. 214 is in the list

Answer14

Part (aiii) · 1 mark

Choose from the list a number that is a multiple of 6.

  1. 1Find a multiple of 6: 6, 12, 18, 24, 30, ...
  2. 230 is in the list

Answer30

Part (aiv) · 1 mark

Choose from the list a number that is prime.

  1. 1Check which numbers are prime: divisible only by 1 and itself
  2. 23 is prime
  3. 323 is prime
  4. 4Both 3 and 23 are in the list

Answer3 or 23

Part (b) · 2 marks

Find the input that gives output 108 for the machine × 5 then + 3.

  1. 1Output = input × 5 + 3
  2. 2108 = input × 5 + 3
  3. 3108 − 3 = 105
  4. 4105 ÷ 5 = 21
  5. 521

Answer21

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