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0580/12 May/Jun 2023, Question 23: Upper and Lower Bounds

Cambridge IGCSE Mathematics 0580 · Paper 12 (Core) · Calculator · 3 marks

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The question, in short

Given masses rounded to different accuracies, complete an inequality for m and show that object B's mass could exceed object A's.

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

Part (a) · 2 marks

Complete the inequality giving the lower and upper bounds for m, where m is 350 kg rounded to the nearest 10 kg.

  1. 1Rounded to the nearest 10 kg, so the bounds are 5 kg either side.
  2. 2Lower bound = 350 − 5 = 345. Upper bound = 350 + 5 = 355.
  3. 3345 ≤ m < 355

Answer345 ≤ m < 355

Part (b) · 1 mark

Using 350 kg to the nearest 10 kg and 348 kg to the nearest kg, show that B's mass may be greater than A's.

  1. 1Lower bound of A = 345 kg
  2. 2B is at least 347.5 kg, e.g. B = 348 kg
  3. 3348 > 345, so if A is 345 kg, B is more than A

AnswerAny correct response e.g. A could be 345

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Also searched as: 0580/12/M/J/23 · 0580_s23_qp_12 · 0580 s23 12 · question 23.
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