Lemmara logoLemmaraWorked solution

4MA1/1HR Jun 2019, Question 5: Prime Factorization

Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 1HR (Higher) · Calculator · 4 marks

اقرأ هذا الحل مشروحاً بالعربي ←

The question, in short

Express 720 in prime factor form with clear working, then determine the least whole number to multiply it by so the result is a perfect square.

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

Part (a) · 3 marks

Break 720 down into a product of primes, showing each step of the working.

  1. 1720 ÷ 2 = 360
  2. 2360 ÷ 2 = 180
  3. 3180 ÷ 2 = 90
  4. 490 ÷ 2 = 45
  5. 545 ÷ 3 = 15
  6. 615 ÷ 3 = 5
  7. 75 ÷ 5 = 1
  8. 82 × 2 × 2 × 2 × 3 × 3 × 5

Answer2 × 2 × 2 × 2 × 3 × 3 × 5

Part (b) · 1 mark

Identify the least whole number multiplier that turns 720 into a square number.

  1. 1Prime factors of 720 are 2⁴ × 3² × 5
  2. 2For a square number, all powers must be even
  3. 3The power of 5 is 1, so multiply by 5 to make it 2
  4. 45

Answer5

Stuck on a step? Read the free lesson: Prime Factorization

Practise more prime factorization 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 prime factorization

Also searched as: 4MA1 1HR June 2019 · 4MA1/1HR · 4ma1 jun19 1hr · question 5.
Lemmara is an independent study tool, not affiliated with or endorsed by Pearson Edexcel. The worked solutions are Lemmara’s own.