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0580/32 May/Jun 2021, Question 1: Compound Interest

Cambridge IGCSE Mathematics 0580 · Paper 32 (Core) · Calculator · 12 marks

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The question, in short

House costs: materials and wages are given as fractions of land cost; work through ratio, individual costs, compound interest on a loan, and selling price with profit.

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

Part (a) · 2 marks

Show the simplified ratio of land to materials to wages is 4 : 6 : 5 using the given fractions.

  1. 1Land : materials : wages = 1 : 1 1/2 : 1 1/4 = 1 : 1.5 : 1.25
  2. 2Multiply each part by 4: 4 : 6 : 5

Answer1 : 1.5 : 1.25 (or 1 : 1 1/2 : 1 1/4), then × 4 gives 4 : 6 : 5

Part (b) · 2 marks

Given wages of $47 500, show the combined cost of land, materials and wages equals $142 500.

  1. 1Land : materials : wages = 1 : 1 1/2 : 1 1/4 = 4 : 6 : 5
  2. 2Wages are 5 parts, so 1 part = 47 500 ÷ 5 = 9500
  3. 3Total = 9500 × (4 + 6 + 5) = 9500 × 15 = 142 500

Answer47 500 ÷ 5 × (4 + 6 + 5) = 142 500

Part (ci) · 2 marks

Using wages of $47 500, work out the cost of the land.

  1. 1Total parts = 4 + 6 + 5 = 15
  2. 21 part = 142 500 ÷ 15 = 9500
  3. 3Land = 4 × 9500 = $38 000

Answer38000

Part (cii) · 1 mark

Using wages of $47 500, work out the cost of the materials.

  1. 1Land : materials : wages = 1 : 1 1/2 : 1 1/4 = 4 : 6 : 5
  2. 2Wages $47 500 are 5 parts, so 1 part = 47 500 ÷ 5 = 9500
  3. 3Materials = 6 × 9500 = 57000

Answer57000

Part (d) · 3 marks

Find the total repayment after 6 years on $28 000 at 5.5% per year compound interest, to the nearest dollar.

  1. 1Amount = 28 000 × (1 + 5.5/100)⁶
  2. 2= 28 000 × 1.055⁶ = 38 607.59…
  3. 3≈ $38 608

Answer38608

Part (e) · 2 marks

Find the selling price when a 27% profit is made on $142 500.

  1. 1Selling price = 142 500 × (1 + 27/100)
  2. 2= 142 500 × 1.27 = $180 975

Answer180975

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Also searched as: 0580/32/M/J/21 · 0580_s21_qp_32 · 0580 s21 32 · question 1.
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