Higher June 2018 Paper 2 Q10
10. Filbert rides his bike at \(x\) km/h for 15 minutes.
He then rides at \((x + 2)\) km/h for half an hour.
The last section of his ride takes a further 15 minutes at \((x - 4)\) km/h.
Show that the total distance of Filbert’s bike ride is \(x\) km.
You must show all your working. [4]
| Scheme | Marks | Comments |
|---|---|---|
| \(x\times\tfrac14 + (x+2)\times\tfrac12 + (x-4)\times\tfrac14\) or \(x\times0.25 + (x+2)\times0.5 + (x-4)\times0.25\) | M2 | M1 for any 2 terms correct (sum need not be shown), or for \(x\times15 + (x+2)\times30 + (x-4)\times15\) or for intention of the correct sum but missing brackets |
| \((=)\ x/4 + x/2 + 1 + x/4 - 1\) or equivalent using decimals | m1 | FT from M1 previously awarded for ‘their correct expansion’ |
| \((=)\ x\) (km) | A1 | From convincing working |
| (4) |