Cubes and cuboids with equal surface areas have larger cuboids.

For example, the length, width and height of a cuboid are 7.5, 5 and 3 respectively.

Surface area: (7.5×5+7.5×3+5×3)×2= 150.

Volume: 7.5×5×3= 1 12.5.

The side length of a cube is 5.

Surface area: 5×5×6= 150.

Volume: 5×5×5= 125

This problem is similar to "a rectangle and a square with equal perimeter, and the square has a larger area".