Juno modified the pentomino pieces to form a cube. As puzzle lovers know, twelve pentomino pieces can form a 3 x 4 x 5 cuboid but those pieces cannot form a cube. Juno changed the ratio of the element of the pieces from a cube to a cuboid, its length of the sides has a ratio of 3 x 4 : 4 x 5 : 5 x 3, now all the twelve pieces can form a cube.
The actual length of the elements is 12 x 15 x 20 mm and it is not a cube anymore but all the twelve pieces still consist of five elements. Then, he named the puzzle Penta Cuboid. The size of the assembled cube is 60 x 60 x 60mm.
There are 3940 solutions to make a 3 x 4 x 5 cuboid using a normal set of solid pentomino. In contrast, Penta Cuboid has a unique solution since Juno carefully chose a malicious combination of the pieces. It will take at least an hour to solve the puzzle even if you are lucky and very talented.
Juno wanted to have a box for Penta Cuboid since the pieces are very slippery and the assembled cube can easily be crumbled. He thought that if he had to use a significant amount of material, it was good to make a box as another puzzle challenge.
T-groove Box is based on his old design that consists of six identical board pieces. To make puzzle more challenging, he changed the shape of the groove from the original X-shape to a T-shape, and then gave variation to the depth of the grooves and width of the board pieces. T-groove Box has a unique solution, not very difficult but still a bit tricky and confusing to solve because all the pieces look quite similar.
The puzzle is sold assembled. The printed solution of the puzzle is enclosed.
Size: 106mm x 106mm x 106mm
Number of pieces: 12 + 6
Material: Utile and Victrian Ash
Designer: Junichi Yananose (Juno)
Origin: Made in Australia
The next three images give you hint to solve Penta Cuboid. Please click the next button if you still would like to see those images.