Lemmara logoLemmaraWorked solution

4MA1/2F Jun 2020, Question 1: Real Numbers

Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 2F (Foundation) · Calculator · 4 marks

اقرأ هذا الحل مشروحاً بالعربي ←

The question, in short

From the given list 1 17 21 25 26 31 39 64, select numbers matching four different properties.

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

Part (a) · 1 mark

Choose an even number from the list.

  1. 1Check which numbers in the list are divisible by 2.
  2. 21 is odd, 17 is odd, 21 is odd, 25 is odd, 26 is even, 31 is odd, 39 is odd, 64 is even.
  3. 3So the even numbers are 26 and 64.

Answer26 or 64

Part (b) · 1 mark

Choose a number from the list that is a multiple of 3.

  1. 1Check which numbers in the list divide by 3.
  2. 21 ÷ 3 = not whole, 17 ÷ 3 = not whole, 21 ÷ 3 = 7, so 21 is a multiple of 3.
  3. 339 ÷ 3 = 13, so 39 is a multiple of 3.
  4. 4So the multiples of 3 are 21 and 39.

Answer21 or 39

Part (c) · 1 mark

Choose a prime number from the list.

  1. 1Check which numbers have exactly two factors: 1 and itself.
  2. 21 is not prime. 17 has factors 1 and 17. 21 = 3×7, not prime. 25 = 5×5, not prime.
  3. 326 = 2×13, not prime. 31 has factors 1 and 31. 39 = 3×13, not prime. 64 is not prime.
  4. 4So the prime numbers are 17 and 31.

Answer17 or 31

Part (d) · 1 mark

Choose a cube number from the list.

  1. 1Check which numbers are cubes of integers.
  2. 21 = 1³, so 1 is a cube number.
  3. 364 = 4³, since 4×4×4 = 64.
  4. 4Other numbers are not cubes.
  5. 5So the cube numbers are 1 and 64.

Answer1 or 64

Stuck on a step? Read the free lesson: Real Numbers

Practise more real numbers 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 real numbers

Also searched as: 4MA1 2F June 2020 · 4MA1/2F · 4ma1 jun20 2f · question 1.
Lemmara is an independent study tool, not affiliated with or endorsed by Pearson Edexcel. The worked solutions are Lemmara’s own.