Holiday Puzzles 2020

 1. DUTCH TREAT In each of these puzzles, place non-overlapping, possibly rotated, copies of the 4×3 dutch flag ( ) in the grid so that there is a connected red path connecting the two given red squares.

 2. SIX OF ONE, HALF DOZEN OF ANOTHER Divide a 9×12 rectangle into a 12 integer-sided squares so that each square is horizontally or vertically adjacent to exactly 3 or 5 other squares, with 6 of each kind.

 3. MURDER MYSTERY An old computer scientist with double vision was found stabbed to death, but he managed to write the following message in blood before he died. Who is the killer?

 4. DOMINOES Remove the doubles from 0-5 set of dominoes and put them in the grid below so that each number is larger than the one below it, and different from the one to its left.

 5. WEIRD CHESS TOUR Start on some square on a 3×3 chessboard. Make 9 moves, visiting every square exactly once and returning to your starting square. Your 9 moves have to be in this order: B-B-N-B-R-N-N-R-R, where B stands for a bishop move (diagonal), R stands for a rook move (horizontal or vertical), and N stands for a knight move (an L-shaped move, 2 squares in one orthogonal direction and 1 square in the other).