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0580/42 Oct/Nov 2021, Question 1: Unit Conversions

Cambridge IGCSE Mathematics 0580 · Paper 42 (Extended) · Calculator · 14 marks

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The question, in short

Work through Malena's fruit trees, ratios, percentages, apple counts, large number notation, and compound interest to find the requested values.

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

Part (ai) · 2 marks

Using 450 trees and the ratio 8:7:3, show the apple tree count is 200.

  1. 1Total parts = 8 + 7 + 3 = 18
  2. 2One part = 450 ÷ 18 = 25
  3. 3Apple trees = 25 × 8 = 200

Answer450/(8 + 7 + 3)×8

Part (aii) · 1 mark

Find how many plum trees Malena has.

  1. 1Plum trees = 25 × 3 = 75

Answer75

Part (aiii) · 2 marks

Calculate the extra pear trees needed to raise their number by 32%.

  1. 1Total parts = 8 + 7 + 3 = 18
  2. 2Pear trees = 7/18 × 450 = 175
  3. 3Extra pear trees = 32/100 × 175 = 56

Answer56

Part (aiv) · 3 marks

With 48.5 kg per tree and 165 g per apple, find total apples from 200 trees to nearest 1000.

  1. 148.5 kg = 48 500 g
  2. 2Apples per tree = 48 500 ÷ 165 = 293.93…
  3. 3Total = 293.93… × 200 = 58 787.8…
  4. 4≈ 59 000 apples (nearest 1000)

Answer59 000

Part (bi) · 1 mark

Write three million and seventy-five thousand in figures.

  1. 13 075 000

Answer3 075 000

Part (bii) · 1 mark

Express the answer from part (b)(i) in standard form.

  1. 13 075 000 = 3.075 × 10⁶

Answer3.075 × 10⁶

Part (c) · 2 marks

Given 37.7 kg in 2020 is 16% more than 2019, find the 2019 mass per plum tree.

  1. 12019 mass × 1.16 = 37.7
  2. 22019 mass = 37.7 ÷ 1.16 = 32.5 kg

Answer32.5

Part (d) · 2 marks

Calculate the value of $1800 invested at 2.1% compound interest for 15 years.

  1. 1Value = 1800 × (1 + 2.1/100)¹⁵
  2. 2= 1800 × 1.021¹⁵ = 2458.43…
  3. 3≈ $2460

Answer2460 or 2458. …

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Also searched as: 0580/42/O/N/21 · 0580_w21_qp_42 · 0580 w21 42 · question 1.
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