On an 8x8 grid I put 21 trominoes of thee different colors. Each group of 7 trominoes has one color. By visual inspection we see the trominoes cover the whole surface except the single empty square marked A2. Two trominoes of the same color are not allowed to touch each other side to side anywhere. In the present arrangement only two pairs of trominoes exist, marked by red color; the others are not forming any pairs. Can you rearrange the trominoes, forming three pairs this time? The single empty square remains in the same position A2.
Transcription of picture:
T = teal, B = blue, R = red, A = A2
A B C D E F G H
1 T T B R R B T T
2 A T B B R B B T
3 B B R R T T R R
4 B T T R T B B R
5 R T B B R B T T
6 R R T B R R B T
7 B T T R T B B R
8 B B R R T T R R