A constant-temperature gas model

At a fixed temperature, the pressure \(p\) kPa of a gas is inversely proportional to its volume \(V\) litres. When \(V=2.4\), \(p=150\).

1. Find the constant \(k\) in \(p=\dfrac{k}{V}\).[1]
2. Find the pressure when the volume is reduced by 20%.[1]
3. A student says that doubling the volume would double the pressure. Explain why the model contradicts this statement.[1]