Similar storage vessels

Two storage vessels are mathematically similar. The smaller vessel is 12 cm high and has capacity \(640\text{ cm}^3\). The larger vessel is 18 cm high.

1. Find the linear scale factor from the smaller vessel to the larger vessel.[1]
2. Find the capacity of the larger vessel in litres.[2]
3. Explain why a mathematically similar vessel with twice the height of the smaller vessel would not have twice its capacity.[1]