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0580/33 May/Jun 2023, Question 8: Direct Proportion in Real Life

Cambridge IGCSE Mathematics 0580 · Paper 33 (Core) · Calculator · 9 marks

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The question, in short

Work with wire measurements: bounds for a rounded length, scaling mass to length, mass of an aluminium volume in standard form, and a percentage length increase.

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

Part (a) · 2 marks

State the lower and upper limits for l, given as 18.7 m rounded to the nearest 10 cm.

  1. 1Nearest 10 cm = 0.1 m, so half is 0.05 m
  2. 218.7 − 0.05 = 18.65 and 18.7 + 0.05 = 18.75
  3. 318.65 ≤ l < 18.75

Answer18.65 ≤ l < 18.75

Part (b) · 3 marks

Find how many metres of wire weigh 900 grams, using 850 m having mass 130.5 kg.

  1. 1900 g = 0.9 kg
  2. 2Length per kg = 850 ÷ 130.5
  3. 3Length = 850 ÷ 130.5 × 0.9 = 5.862… ≈ 5.86 m

Answer5.86 or 5.862…

Part (c) · 2 marks

Find the mass of 6000 cm³ of aluminium, density 2.7 g per cm³, in standard form.

  1. 1Mass = 2.7 × 6000 = 16 200 g
  2. 2= 1.62 × 10⁴ g

Answer1.62 × 10⁴

Part (d) · 2 marks

Find the percentage increase when a 12 m wire stretches to 12.017 m.

  1. 1Increase = 12.017 − 12 = 0.017
  2. 20.017/12 × 100 = 0.14166…
  3. 3≈ 0.142%

Answer0.142 or 0.1416 to 0.1417

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Also searched as: 0580/33/M/J/23 · 0580_s23_qp_33 · 0580 s23 33 · question 8.
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