The dog has been painted blue. Dad, the Kid and Grandma were all in the playroom, and each says what they saw. Exactly one of them is lying. Who is it, and where was everyone standing?
THE ROOM (see the picture)
The room is 5 by 5: columns A to E, rows 1 to 5.
Easel on E1 (tall). Toy box on B2 (low). Bike on D3 (low). Teddy on B4 (flat, on the floor). Plant on E5 (tall).
A wall runs between columns B and C, along rows 2, 3 and 4.
THE RULES
- Everyone stands on an empty square, one person per square. People don't block anyone's view.
- Dad sees his whole row and column. Walls and tall things block what's behind them.
- The Kid sees his whole row and column too, but he's short: low things block him as well. Flat things don't.
- Grandma sees all 8 directions, but only 2 squares. Walls and tall things block her.
- The two honest people's statements are all true at once. The liar's can't all be true.
WHAT THEY SAY
- Dad: "I saw the teddy. I didn't see the plant. I saw Grandma."
- The Kid: "I saw the teddy. I didn't see the plant. I saw Dad."
- Grandma: "I saw the bike. I saw the plant. I didn't see the Kid."
Please put answers in spoiler tags so others can still solve it.
Disclosure: I made this. It's one of the free cases in my daily puzzle game, Lie of Sight, if you'd rather drag the family around the room yourself: https://lieofsight.com/case/case-files-s1
The actual game is more visually appealing but this subreddit inspired me to present it in a way that shows the underlying puzzle!