Foundation January 2022 Paper 2 Q22
22 Find the lowest common multiple (LCM) of 28, 42 and 63
Show your working clearly.
(3)
| Scheme | Marks |
|---|---|
| \(2^2 \times 7\) or \(2 \times 3 \times 7\) or \(3^2 \times 7\) oe or showing at least 5 correct multiples across at least 2 lists (excluding 28, 42, 63) (28) 56, 84, 112, 140, 168, 196, 224, 252 (42) 84, 126, 168, 210, 252 (63) 126, 189, 252 | M1 |
| \(2^2 \times 7\) and \(2 \times 3 \times 7\) and \(3^2 \times 7\) or showing at least 9 correct multiples across all 3 lists (excluding 28, 42, 63) (28) 56, 84, 112, 140, 168, 196, 224, 252 (42) 84, 126, 168, 210, 252 (63) 126, 189, 252 | M1 |
| Working required Answer: 252 | A1 |
| (3) | |
| (3 marks) |
Notes
M1: accept prime factors seen in factor tree or correct position in Venn diagram for at least one of the numbers given with no other numbers for that number incorrectly placed
M1: accept prime factors seen in factor tree or correct position in Venn diagram for all 3 of the numbers given with no other numbers incorrectly placed
A1: or \(2^2 \times 3^2 \times 7\) Dep on M1
Alternative
| Scheme | Marks | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| M1 | ||||||||||||||||||||||||
| M1 | ||||||||||||||||||||||||
| Working required Answer: 252 | A1 |
M1: For one correct row in table
eg division by 7 gives 4, 6, 9
M1: Fully correct table – need only go as far as top table – we want to see prime factors along the side or prime factors along the sides and bottom (condone 1’s)
A1: or \(2^2 \times 3^2 \times 7\) Dep on M1