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4024/12 Oct/Nov 2020, Question 18: Speed, Distance and Time

Cambridge O Level Mathematics 4024 · Paper 12 (Non-calculator) · Non-calculator · 5 marks

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The question, in short

Using Safira's distance–time graph from home to a shop and back between 08 15 and 08 50, find her stop time, her brother's journey graph and meeting distance, and her walking speed in km/h.

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

Part (a) · 1 mark

Find how many minutes Safira spends stationary at the shop.

  1. 1The graph is horizontal from 08 30 to 08 35
  2. 2Time in shop = 5 minutes

Answer5

Part (bi) · 1 mark

Draw the graph of her brother's walk to the shop, leaving at 08 30 at Safira's speed.

  1. 1Safira takes 15 minutes to walk 1200 m, so the brother does too
  2. 2Draw a straight line from (08 30, 0) to (08 45, 1200)

Answerline from (08 30, 0) to (08 45, 1200)

Part (bii) · 1 mark

Find how far her brother is from the shop when he meets Safira.

  1. 1The lines cross at 08 40, at 800 m from home
  2. 2Distance from shop = 1200 − 800 = 400 m

Answer400

Part (c) · 2 marks

Calculate Safira's walking speed to the shop in km/h.

  1. 1Distance = 1200 m = 1.2 km, time = 15 min = 1/4 hour
  2. 2Speed = 1.2 ÷ 1/4 = 4.8 km/h

Answer4.8 or 4 4/5 or 24/5

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Also searched as: 4024/12/O/N/20 · 4024_w20_qp_12 · 4024 w20 12 · question 18.
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