June 2025 Paper 1 Q9
9 3-digit integers are made using three different digits.
The digits are chosen from \(\quad 1, 2, 3, 4, 5, 6, 7, 8, 9\)
How many more odd integers than even integers can be made? [3 marks]
| Answer | Mark | Comments |
|---|---|---|
| Alternative method 1: by considering the third digit | ||
| \(8 \times 7 \times 5\) or 280 or \(8 \times 7 \times 4\) or 224 | M1 | |
| \(8 \times 7 \times 5\) or 280 and \(8 \times 7 \times 4\) or 224 or \(8 \times 7 \times (5 - 4)\) | M1dep | |
| 56 | A1 | SC1 81 |
| Alternative method 2: splitting the total in the correct ratio | ||
| \(9 \times 8 \times 7\) | M1 | |
| \(\dfrac{504}{9}\) or 280 and 224 | M1dep | |
| 56 | A1 | SC1 81 |
Additional guidance
| Up to M1 may be awarded for correct work with no answer or incorrect answer, even if this is seen amongst multiple attempts | |
| Listing outcomes with incorrect answer (could still gain M1 from above if part of multiple attempts) | M0A0 |
| 56 from clearly incorrect working | M0A0 |
| 56 with no incorrect working but some omitted working – this could come from listing groups of outcomes but missing some groups out (that give the same answers so cancel) | M2A1 |
| Listing outcomes with correct answer | M2A1 |