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0580/33 Oct/Nov 2021, Question 7: HCF and LCM

Cambridge IGCSE Mathematics 0580 · Paper 33 (Core) · Calculator · 11 marks

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The question, in short

Number skills: write a number in figures, work out change from $5, evaluate a root and powers, find prime factors of 130, and use the LCM for two bells.

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

Part (a) · 1 mark

Turn a six-digit number given in words into figures.

  1. 1603 821

Answer603 821

Part (b) · 2 marks

Change from $5 after 8 pens at 47 cents.

  1. 18 × 0.47 = $3.76
  2. 25 − 3.76 = $1.24

Answer1.24

Part (ci) · 1 mark

Square root of 81.

  1. 1√81 = 9

Answer9

Part (cii) · 1 mark

6 cubed.

  1. 16³ = 6 × 6 × 6 = 216

Answer216

Part (ciii) · 1 mark

3 to the power 0.

  1. 13⁰ = 1

Answer1

Part (d) · 2 marks

130 as a product of primes.

  1. 1Divide by the smallest prime: 130 ÷ 2 = 65
  2. 265 ÷ 5 = 13, and 13 is prime
  3. 3130 = 2 × 5 × 13

Answer2 × 5 × 13

Part (e) · 3 marks

Bells every 12 and 14 minutes, together at 09 30: when next together?

  1. 112 = 2² × 3 and 14 = 2 × 7
  2. 2LCM = 2² × 3 × 7 = 84 minutes = 1 h 24 min
  3. 309 30 + 1 h 24 min = 10 54

Answer10 54

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Also searched as: 0580/33/O/N/21 · 0580_w21_qp_33 · 0580 w21 33 · question 7.
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