Lemmara logoLemmaraWorked solution

4MA1/1FR Jan 2020, Question 17: Set Notation

Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 1FR (Foundation) · Calculator · 3 marks

اقرأ هذا الحل مشروحاً بالعربي ←

The question, in short

Using sets B, G and W of letters, find a union and an intersection with a complement, then judge whether a stated three-set intersection is empty, giving a reason.

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

Part (ai) · 1 mark

List every member of the set B ∪ G.

  1. 1List all elements in B or G or both: b, l, u, e from B; g, r, y from G; e is common so listed once
  2. 2Combine: b, l, u, e, g, r, y

Answerb, l, u, e, g, r, y

Part (aii) · 1 mark

List every member of the set W ∩ G ′.

  1. 1G′ is everything not in G: so letters not g, r, e, y
  2. 2W = {w, h, i, t, e}; remove any that are in G (e is in G)
  3. 3So W ∩ G′ excludes e, leaving w, h, i, t

Answerw, h, i, t

Part (b) · 1 mark

Decide if Serena's statement B ∩ G ∩ W = ∅ is correct and justify your decision.

  1. 1e is in B, in G and in W
  2. 2So B ∩ G ∩ W = {e}, which is not empty
  3. 3No, e is in all three sets

AnswerNo, e is in all three sets

Stuck on a step? Read the free lesson: Set Notation

Practise more set notation questions

Real 4MA1 past-paper questions, marked on your working like the exam, with a worked solution for every part.

Practise free on Lemmara

More past-paper questions on set notation

Also searched as: 4MA1 1FR January 2020 · 4MA1/1FR · 4ma1 jan20 1fr · question 17.
Lemmara is an independent study tool, not affiliated with or endorsed by Pearson Edexcel. The worked solutions are Lemmara’s own.