Numeracy Foundation June 2017 Unit 2 Q10
10. Alun has made his own conversion graph to change knots to miles per hour.
(a) Use Alun’s conversion graph to write 150 knots in miles per hour. [1]
(b)
Nikita thinks Alun’s conversion graph may be inaccurate.
Nikita knows that 1000 knots is 1150.779 miles per hour, correct to 3 decimal places.
Convert 20 knots to miles per hour
- using Alun’s conversion graph, and then
- using Nikita’s values.
Calculate the difference, in miles per hour, between your answers.
Give your answer correct to 2 decimal places.
You must show all your working. [4]
| Scheme | Marks | Comments |
|---|---|---|
| 172.5 (miles per hour) | B1 | ISW |
| Scheme | Marks | Comments |
|---|---|---|
| Alun 23 (miles per hour) | B1 | |
| Nikita 20 × 1150.779 ÷ 1000 or 1150.779 ÷ 50 or equivalent | M1 | |
| 23.01(558..) or 23.02 (miles per hour) | A1 | |
| Difference 0.02 (miles per hour to 2 d.p.) | B1 | CAO Alternative Sight of difference 0.000779 B1 Difference = 0.000779 × 20 M1 = 0.01(558) A1 0.02 mph (2dp) B1 CAO |