4MA0 Higher January 2013 Paper 4 Q24
24 On Monday, Nalim made a journey.
On Tuesday, she made the same journey.
Her average speed on Tuesday was 25% greater than her average speed on Monday.
Calculate the percentage reduction in the time her journey took on Tuesday compared with Monday.
(3)
| Scheme | Marks |
|---|---|
\(\dfrac{1}{1.25}\) oe eg \(\dfrac{1}{\tfrac{5}{4}}\), \(\tfrac{4}{5}\), 0.8(0), \(\dfrac{100}{125}\), 80%, \(t_1 = \dfrac{d}{s}\) and \(t_2 = \dfrac{d}{(1 + 0.25)s}\) or \(\dfrac{t_2}{t_1} = 0.8\) | M1 |
| 1 − 0.8 oe eg \(1 - \tfrac{4}{5}\), 100% − 80% | M1 |
| 20 | A1 |
| (3) |
Notes
A1: cao
Alternative method (assigns values to distance and average speed)
M1 for calculating both times correctly
M1 (dep) for finding \(\dfrac{\text{Mon time} - \text{Tues time}}{\text{Mon time}}\)