Foundation November 2022 Paper 3 Q16
16 A ball of dough is left to rise before it is baked.
The graph shows the height of the ball of dough over the first 20 minutes.
(a) Work out the gradient of the line as a decimal, giving the units of your answer.
Show how you work out your answer. [3]
Show how you work out your answer. [3]
(b) A baker works out the height of the ball of dough at the end of 25 minutes as 14 cm.
(i) Use your gradient to show that the baker could be correct. [2]
(ii) What assumption has the baker made? [1]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 0.2 or 0.19 to 0.20 | 2 | M1 for \(\dfrac{3.8 \text{ to } 4}{20}\) oe If 0 scored, SC1 for triangle with incorrect values marked and their \(\dfrac{\text{rise}}{\text{run}}\) or \(\dfrac{\text{rise}}{\text{run}}\) with answer in range \(0.18 \leqslant g \lt 0.19\) | e.g. \(\dfrac{1.9 \text{ to } 2}{10}\) e.g. \(\dfrac{13}{20}\) with no triangle scores 0 e.g. \(\dfrac{13}{20}\) with 13 and 20 marked on triangle scores SC1 e.g \(\dfrac{2.1}{11.6}\) and answer 0.181... SC1 |
| cm per minute or cm/min | 1 | Mark for units still available even if wrong gradient | |
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| (i) \(5 \times\) their gradient | M1 | FT their gradient which is a number | Alternative method M2 for \(25 \times (0.19\) to \(0.2) + 9\) with answer that rounds to 14 or M1 for 25 × their gradient + 9 with answer that does not round to 14 |
| 13 + their 1 giving answer that rounds to 14 | M1 | ||
| (ii) Continues to rise at same rate oe or Rises 0.2 cm every minute oe | 1 | FT their gradient if figures quoted | Must imply constant increase [in height] or continued pattern If figures used must be correct or from their gradient Accept The pattern continues oe The dough rises consistently oe The dough will rise I cm in 5 minutes |