Pentomino postcard competition
By Edo Timmermans.
Try to place the 12 pentominoes

inside the largest possible rectangle, in such a way that the pentominoes divide the rectangle in 5 parts of equal size.
There may not be more then 5 open areas; also open areas are not allowed to touch each other in a corner.
The pentominoes must form one shape, so that from any pentomino there is a pentomino path to any other pentomino.
Find the largest solution in which there is an open area in the centre, enclosed by pentominoes.

This Excel file will make searching for a solution a bit easier.
To download it click with the right mouse button and choose ‘Save target as ...’ to save this Excel file on your hard disk or diskette.

An help in searching for solutions is the program “FlatPoly2”. You can download it from the homepage of Aad van de Wetering, Driebruggen.