1) 5 x 12 rectangle*
This 5×12 rectangle consists of the twelve different figures of 5 squares each. The original borders have been removed.
Each figure contains the letters A, B, C, D and E exectly once.
Can you find restore the borders between the twelve figures?
For those of you who are not familiar with them, here are the 12 possible pentominoes, or possible figures of 5 squares.
This type of puzzle was, as far as I know, first published in the British magazine Games and Puzzles, issue no 50, july 1976.
There is a type of puzzle where all bones from the double 6 set are laid down in a 7×8 square. Sometimes that type of puzzle is called dominosa. You can find a couple of them on my homepage, the domino plaza. Because the type of puzzle is very similar, I have christened this type of puzzle pentominosa.
Please do not list the solution(s). In all other respects, I welcome discussion, listing alternative solutions, and I espoecially welcome your solution times, as that helps me to get an impression of the difficulty.