Foundation June 2017 Paper 2 Q20
20 Olly drove 56 km from Liverpool to Manchester.
He then drove 61 km from Manchester to Sheffield.
Olly’s average speed from Liverpool to Manchester was 70 km/h.
Olly took 75 minutes to drive from Manchester to Sheffield.
(a) Work out Olly’s average speed for his total drive from Liverpool to Sheffield. (4)
Janie drove from Barnsley to York.
Janie’s average speed from Barnsley to Leeds was 80 km/h.
Her average speed from Leeds to York was 60 km/h.
Janie says that the average speed from Barnsley to York can be found by working out the mean of 80 km/h and 60 km/h.
(b) If Janie is correct, what does this tell you about the two parts of Janie’s journey? (1)
| Answer | Mark | Notes |
|---|---|---|
| 57.1 | P1 | for a process to find time from Liverpool to Manchester, eg. \(56 \div 70\ (= 0.8\) (hrs) or 48 (mins)) |
| P1 | for a process to find the total distance, eg \(56 + 61\ (= 117)\) or the total time, eg \(\text{``}48\text{''} + 75\ (= 123)\) or \(\text{``}0.8\text{''} + \dfrac{75}{60}\ (= 2.05)\), with consistent units of time | |
| P1 | (dep P2) for a correct process to find average speed with consistent units of time, eg. \(\text{``}117\text{''} \div \text{``}2.05\text{''}\) or \(\text{``}117\text{''} \div \text{``}123\text{''}\) | |
| A1 | for answer in the range 57 to 57.1 |
| Answer | Mark | Notes |
|---|---|---|
| explanation | C1 | for explaining that the time taken for the two parts of the journey must be the same or the distance from Leeds to York is \(\frac{3}{4}\) the distance from Barnsley to Leeds oe (corrected from the printed mark scheme: it says “\(\frac{3}{4}\) the distance from Barnsley to York”; with equal times the Leeds to York distance is \(\frac{3}{4}\) of the Barnsley to Leeds distance, or \(\frac{3}{7}\) of the whole journey) |