Foundation November 2017 Paper 1 Q20
20.
(a)
The variables \(x\) and \(y\) are connected by the equation \(y = \dfrac{25}{x}\).
(i)
Circle the correct statement. [1]
\(x\) is inversely proportional to 25 \(x\) is directly proportional to \(y\)
\(y\) is inversely proportional to \(x\) \(y\) is directly proportional to \(x\)
(ii) Find the value of \(x\) when \(y = 100\). [2]
(b) 
The distance-time graph shows the start of a journey.
Work out the speed of this part of the journey in metres per second. [2]
| Scheme | Marks | Comments |
|---|---|---|
| (i) \(y\) is inversely proportional to \(x\) indicated | B1 | |
| (ii) (\(x\) =) 0.25 or equivalent | B2 | B1 for \(100 = \dfrac{25}{x}\) seen Do not accept \(y\) = 0.25 or equivalent |
| Scheme | Marks | Comments |
|---|---|---|
| \(\dfrac{4}{0.8}\) or equivalent | M1 | Allow e.g. ‘1 metre every 0.2 seconds.’ |
| 5 (m/s) or equivalent | A1 | |
| (5) |