Foundation June 2019 Paper 2 Q21
21 Beth drives 200 miles in 4 hours.
She drives the first 18 miles at an average speed of 36 mph
Work out her average speed for the rest of the journey. [3 marks]
| Answer | Mark | Comments |
|---|---|---|
| Alternative method 1 | ||
| \(18 \div 36\) or 0.5 or 30 | M1 | oe implied by 3.5 or 3 h 30 min or 3.3(0) or 210 seen |
| \(\dfrac{200 - 18}{4 - \text{their } 0.5}\) or \(\dfrac{182}{3.5}\) or \(\dfrac{200 - 18}{4 \times 60 - \text{their } 30}\) or \(\dfrac{182}{210}\) or 0.86(6…) or 0.87 | M1dep | oe method for miles per hour or miles per minute implied by \(\dfrac{182}{3 \text{ h } 30 \text{ min}}\) or \(\dfrac{182}{3.3(0)}\) |
| 52 | A1 | |
| Alternative method 2 | ||
| \(18 \div 36\) or 0.5 or 30 | M1 | implied by 7 |
| \(\dfrac{200}{4} + \dfrac{50 - 36}{7}\) or \(50 + 2\) | M1dep | oe |
| 52 | A1 | |
Additional guidance
| Allow the first mark even if not subsequently used | |
| Ignore units for the M marks | |
| Answer 0.86(6…) or 0.87 | M1M1A0 |
| Answer 0.86(6…) or 0.87 with mph crossed out and replaced by miles per min oe | M1M1A1 |
| Working for 52 then \((52 + 36) \div 2\) | M1M1A0 |
| NB \(50 + 2 = 52\) from \(200 \div 4 = 50\) and \(36 \div 18 = 2\) | Zero |