The aim of this quiz is to place Xs and Os correctly into each cell on the 3×3 grid, as in a tic-tac-toe game. A player wins when having occupied the entire row, column, or diagonal with the same symbol. Otherwise the game ends in a draw.
Cell 1 tells you three things at the start of the game:
- The game ended in a draw.
- ‘X’ occupies opposite corners.
- No other hints are necessary for solving the puzzle.
Since Cell 1 is a corner and is an ‘O,’ we know that Cell 3 and Cell 7 must both be ‘X.’
Because the game ended in a draw, we can conclude that Cell 5 must be an ‘O’ in order to prevent a tic-tac-toe from occurring with Cells 3 and 7.
Knowing the rules of tic-tac-toe, we can fill in the remaining squares using just logic in order to force a draw.
Cell 9 must be an ‘X‘ to block the tic-tac-toe for 1 and 5.
Cell 6 must be an ‘O’ to block the tic-tac-toe for 3 and 9.
Cell 8 must be an ‘O’ to block the tic-tac-toe for 7 and 9.
Cell 2 must be an ‘X’ to block the tic-tac-toe for 5 and 8.
Cell 4 must be an ‘X’ to block the tic-tac-toe for 5 and 6.
The final layout of the tic-tac-toe board is:
O X X
X O O
X O X