A cube of edge 6 cm and a cuboid with a 4 cm × 3 cm base hold exactly the same volume. Find the height of the cuboid.

Cube volume = $6^3=216{\text{cm}}^3$. Cuboid base area = $4\times 3=12{\text{cm}}^2$, so height = 216 ÷ 12 = 18 cm. Trap 3 cm: squaring the edge instead of cubing it (36 ÷ 12). Trap 6 cm: assuming the cuboid must be as tall as the cube. Trap 12 cm: dividing 216 by 18 — the base area and the answer have been swapped.