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4024/12 May/Jun 2022, Question 14: Standard Form

Cambridge O Level Mathematics 4024 · Paper 12 (Non-calculator) · Non-calculator · 3 marks

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The question, in short

Order four given numbers from smallest to largest, then find the values of a and b in a standard form division equation.

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

Part (a) · 1 mark

Arrange 2000, 0.002, 2 × 10⁻⁴ and 2 × 10⁻² in increasing order of size.

  1. 12 × 10⁻⁴ = 0.0002 and 2 × 10⁻² = 0.02
  2. 2Order: 2 × 10⁻⁴, 0.002, 2 × 10⁻², 2000

Answer2 × 10⁻⁴, 0.002, 2 × 10⁻², 2000

Part (b) · 2 marks

Given a × 10⁻⁷ ÷ (5 × 10ᵇ) = 4 × 10⁻¹⁶, find the values of a and b.

  1. 1a × 10⁻⁷ ÷ (5 × 10ᵇ) = (a/5) × 10⁻⁷⁻ᵇ
  2. 24 × 10⁻¹⁶ = 0.4 × 10⁻¹⁵, so a/5 = 0.4 and −7 − b = −15
  3. 3a = 2, b = 8

Answera = 2, b = 8

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Also searched as: 4024/12/M/J/22 · 4024_s22_qp_12 · 4024 s22 12 · question 14.
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