Foundation June 2019 Paper 1 Q9
9
(a) Write down all the factors of 18 [2 marks]
(b) Work out the lowest common multiple (LCM) of 12 and 15 [2 marks]
| Answer | Mark | Comments |
|---|---|---|
| 1, 2, 3, 6, 9, 18 | B2 | B1 the 6 correct values, some or all repeated, with no incorrect values or 5 or 6 correct values with up to 2 incorrect values or 4 correct values with 0 or 1 incorrect values or 3 correct values with 0 incorrect values |
Additional guidance
| Use of products or ‘coordinates’ is B1 max for at least 2 correct products with 0 or 1 incorrect products eg \(1 \times 18,\ 2 \times 9,\ 3 \times 6\) eg \(1 \times 18,\ 2 \times 9,\ 3 \times 6,\ 4 \times 4\) | B1 B1 |
| Lists with repeated values cannot score B2, but ignore repeated values in any format for B1 eg 1, 2, 3, 3 eg \(1 \times 18,\ 2 \times 9,\ 3 \times 6,\ 18 \times 1,\ 9 \times 2,\ 6 \times 3\) | B1 B1 |
| If a prime factor ‘tree’ or similar is used, factors must be identified |
| Answer | Mark | Comments |
|---|---|---|
| 60 | B2 | B1 any common multiple of 12 and 15 eg 120, 180 B1 at least the first two multiples correct for each of 12 and 15 (ignore errors after first two) B1 \((12 =)\ 2(\times)2(\times)3\) and \((15 =)\ 5(\times)3\) and \(2(\times)2(\times)5(\times)3\ ((\times)3)\) (or the equivalent work seen in a correct Venn diagram) |
Additional guidance
Answer 60 with error(s) seen may be B0 or B1 but cannot be B2
These error(s) may occur after the 60 – but cannot be ignored
If they have listed both multiples and factors, they must choose multiples to score
For B2, 60 must be chosen and not just at the end of a list of multiples