CAPE Pure Mathematics Unit 1 · May/June 2014 · Paper 1 · Question Q11

Which of the following sets of ordered pairs represent functions? \begin{align*} \text{I.} & \quad \{(-1, 1), (0, 2), (1, 3), (4, 6)\} \\ \text{II.} & \quad \{(-2, 4), (1, 1), (1, 4), (2, 4)\} \\ \text{III.} & \quad \{(-1, 1), (0, 0), (1, 1), (-3, 9)\} \\ \text{IV.} & \quad \{(-2, 5), (-1, 5), (0, 5), (1, 5)\} \end{align*}

1. (A)I and II only
2. (B)II and III only
3. (C)I, II and III only
4. (D)I, III and IV only