Elementary Mathematics Dorofeev -

But ? 2. The First Attempt You try. Place a tromino horizontally in the top row. Then another. You quickly get stuck — the missing corner leaves an awkward gap. After some attempts, you suspect it’s impossible .

Can you tile the remaining 24-unit shape with 1×3 "trominoes" (three squares in a straight line)? elementary mathematics dorofeev

Now remove the top-left corner (1,1). Its color is (1+1) mod 3 = 2 mod 3 = Color 2? Wait — careful: (1+1)=2, so 2 mod 3 = 2 — yes, Color 2. So after removal: Color 0: 9 Color 1: 8 Color 2: 7 (since we removed one from Color 2) Each 1×3 tromino, no matter how you place it (horizontal or vertical), covers exactly one square of each color . Place a tromino horizontally in the top row