Foundation November 2017 Paper 2 Q9
9 Karl has twin sisters.
The sum of the ages of Karl and his twin sisters is 39
In 4 years’ time the twins will be 18
How old will Karl be in 4 years’ time? [3 marks]
| Answer | Mark | Comments |
|---|---|---|
| Alternative method 1 | ||
| 18 – 4 or 14 seen | M1 | oe eg 4 + 14 = 18 |
| \(39 - 2 \times\) their 14 or \(39 - 28\) or 11 | M1dep | oe eg 14, 14, 11 |
| 15 | A1 | |
| Alternative method 2 | ||
| \(39 + 3 \times 4\) or \(39 + 12\) or 51 | M1 | |
| their \(51 - 2 \times 18\) or their \(51 - 36\) | M1dep | |
| 15 | A1 | |
Additional guidance
| 14 may be implied by eg twins = 28 (but not just 28 seen) | M1 |