Foundation June 2017 Paper 1 Q19
19
(a) Use \(\quad 8\text{ km/h} = 5\text{ mph} \quad\) to convert 96 km/h to mph [2 marks]
(b) \(x\text{ km/h} = y\text{ mph}\)
Use \(\quad 8\text{ km/h} = 5\text{ mph} \quad\) to write a formula for \(y\) in terms of \(x\). [2 marks]
| Answer | Mark | Comments |
|---|---|---|
| \(96 \div 8\) or 12 or \(8 \times 12 = 96\) or \(96 \times 5\) or 480 or \(96 \div 8 \times 5\) or \(8 \div 5\) or 1.6 or \(\dfrac{8}{5}\) or \(5 \div 8\) or 0.625 or \(\dfrac{5}{8}\) | M1 | oe |
| 60 | A1 |
Additional guidance
Build up method must be complete at least as far as, and must include, 96, but allow one error in the build up of 5s (oe) for M1
| M1 A0 |
| Answer | Mark | Comments |
|---|---|---|
| \(\dfrac{y}{x} = \dfrac{5}{8}\) or \(\dfrac{x}{y} = \dfrac{8}{5}\) or \(8y = 5x\) or \(\dfrac{5x}{8}\) or \(0.625x\) or \((x =)\, \dfrac{8y}{5}\) or \((x =)\ 1.6y\) or \(y = kx\) and \(k = \dfrac{5}{8}\) or \(8 \div 5\) incorrectly evaluated and then \(y = \dfrac{x}{\text{their incorrect evaluation}}\) | M1 | oe |
| \(y = \dfrac{5x}{8}\) | A1 | oe in form \(y = \mathrm{f}(x)\) eg \(\;y = 0.625x\;\) or \(\;y = \dfrac{x}{1.6}\;\) or \(\;y = 5x \div 8\) or \(\;y = x \div (8 \div 5)\;\) or \(\;y = x \div 8 \times 5\) |
Additional guidance
| \(y = \dfrac{5}{8} \times x\;\) or \(\;y = \dfrac{x}{8} \times 5\;\) or \(\;y = x \div 1.6\) | M1A1 |
| \((y =)\, \dfrac{x5}{8}\;\) or \(\;(y =)\ x\dfrac{5}{8}\;\) or \(\;y = \dfrac{5}{8}\) of \(x\) | M1A0 |
| Condone units for M1 only | |
| Do not ignore further work eg \(\;y = x \div (8 \div 5)\;\) then \(\;y = x \div 8 \div 5\) | M1A0 |