Multiple choice

Which of the following is the highest common factor of 21 and 56?

  1. 1

  2. 3

  3. 7

  4. 9
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Prime factorisation of 21 = 3 × 7 Prime factorisation of 56 = 2 × 2 × 2 × 7 HCF of 21 and 56 = 7

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