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0580/21 Oct/Nov 2025, Question 10: Set Notation

Cambridge IGCSE Mathematics 0580 · Paper 21 (Extended) · Non-calculator · 2 marks

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The question, in short

Using ℰ = {integers n : 1 ≤ n ≤ 8}, A = {factors of 12} and B = {odd numbers}, find a set intersection and a count of a union.

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Part (a) · 1 mark

Find A ∩ B, the elements common to the factors of 12 and the odd numbers.

  1. 1A = {1, 2, 3, 4, 6}, B = {1, 3, 5, 7}
  2. 2A ∩ B = {1, 3}

Answer1, 3

Part (b) · 1 mark

Find n(A′ ∪ B), the number of elements in the union of the complement of A with B.

  1. 1A′ = {5, 7, 8}
  2. 2A′ ∪ B = {1, 3, 5, 7, 8}
  3. 3n(A′ ∪ B) = 5

Answer5

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Also searched as: 0580/21/O/N/25 · 0580_w25_qp_21 · 0580 w25 21 · question 10.
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