Foundation June 2025 Paper 1 Q11
11 Here is a list of three numbers.
\[8 \qquad 15 \qquad 10\]A fourth number is added to the list.
The mean of the four numbers is 13.
Work out the fourth number. [3]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 19 | 3 | M2 for \((13 \times 4) - (8 + 15 + 10)\) oe or for \(8 + 15 + 10 + 19 = 52\) or \(\dfrac{8 + 15 + 10 + 19}{4} = 13\) or M1 for \(13 \times 4\) maybe implied by 52 or for \(\dfrac{8 + 15 + 10 + x}{4} = 13\) or better or for \(\dfrac{8 + 15 + 10 + c}{4}\) correctly evaluated for their value of \(c\) | Correct final answer by trials scores 3 |