4MA0 Higher June 2016 Paper 4 Q10

EdexcelHigherOld spec2 marksProperties of Numbers

10 The highest common factor (HCF) of 140 and \(x\) is 20
The lowest common multiple (LCM) of 140 and \(x\) is 420

Find the value of \(x\).

(2)

Mark scheme

M1: For identifying the prime factors for 2 of the 3 numbers 20,140,420 (can be implied by a factor tree, repeated division or Venn diagram) or

For a complete Venn diagram for \(x\) and 140 with 20 in the intersection or

\(x = 20 \times 3\) or

\(20 \times 7 \times y = 420\) or

\(\dfrac{420}{20 \times 7}\) or

At least the 1st 3 multiples of 20 or

\(140x = 420 \times 20\) oe

A1: Allow 2×2×3×5