Question 6
Three boards have these rows. Board 1 (top): 2 5 9 / 7 6 4 / 1 3 8. Board 2 (bottom left): 9 4 3 / 2 6 8 / 1 5 7. Board 3 (bottom right): 5 9 1 / 4 6 3 / 7 2 8. Circle a winning tic-tac-toe line (three in a row) on each board so that one board has a diagonal win, one a horizontal win and one a vertical win, and the nine circled numbers are 1 to 9 once each. Which board (1, 2 or 3) has the diagonal win? Answer with a natural number.
