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0580/31 Oct/Nov 2022, Question 1: Using a Calculator

Cambridge IGCSE Mathematics 0580 · Paper 31 (Core) · Calculator · 12 marks

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The question, in short

Helga's knitting purchases and squares: complete a bill, find change from $50, show total squares from a ratio, then use a 6 by 4 blanket for percentage and perimeter.

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

Part (a) · 3 marks

Complete the bill: 2 pairs of needles at $4.95 each, 6 buttons at $0.65 each, 1 pattern at $3.60, and the total.

  1. 1Needles: 2 × 4.95 = 9.90
  2. 2Buttons: 6 × 0.65 = 3.90
  3. 3Total: 9.90 + 3.90 + 3.60 = 17.40

Answer9.90, 3.90, Total 17.40

Part (b) · 2 marks

Find the change from a $50 note after buying 8 balls of wool at $3.12 each.

  1. 1Cost of wool = 8 × 3.12 = $24.96
  2. 2Change = 50 − 24.96 = $25.04

Answer25.04

Part (c) · 2 marks

White:pink:blue = 5:3:2 with 30 blue squares; show the total number of squares is 150.

  1. 12 parts = 30, so 1 part = 30 ÷ 2 = 15
  2. 2Total parts = 5 + 3 + 2 = 10
  3. 3Total squares = 15 × 10 = 150

Answer30 ÷ 2 × (5 + 3 + 2) = 150

Part (di) · 2 marks

A blanket is 6 squares long and 4 wide; calculate the percentage of the 150 squares used.

  1. 1Squares used = 6 × 4 = 24
  2. 224/150 × 100 = 16%

Answer16

Part (dii) · 3 marks

Each square has side 15 cm; work out the blanket's perimeter in metres.

  1. 1Length = 6 × 15 = 90 cm, width = 4 × 15 = 60 cm
  2. 2Perimeter = 2(90 + 60) = 300 cm
  3. 3300 cm = 3 m

Answer3

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Also searched as: 0580/31/O/N/22 · 0580_w22_qp_31 · 0580 w22 31 · question 1.
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