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4MA1/2H Jan 2019, Question 6: HCF and LCM

Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 2H (Higher) · Calculator · 4 marks

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The question, in short

Find the HCF of 96 and 120, then use the prime factor forms of A, B and C to find their LCM.

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Part (a) · 2 marks

Find the highest common factor of 96 and 120.

  1. 196 = 2 × 2 × 2 × 2 × 2 × 3
  2. 2120 = 2 × 2 × 2 × 3 × 5
  3. 3HCF = 2 × 2 × 2 × 3
  4. 424

Answer24

Part (b) · 2 marks

Using A = 2³ × 5 × 7² × 11, B = 2⁴ × 7 × 11 and C = 3 × 5², find the LCM of A, B and C.

  1. 1A = 2³ × 5 × 7² × 11
  2. 2B = 2⁴ × 7 × 11
  3. 3C = 3 × 5²
  4. 4LCM = 2⁴ × 3 × 5² × 7² × 11
  5. 516 × 3 × 25 × 49 × 11
  6. 6646800

Answer646800

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