Imagine a multiplication table (like the one below, except it continues on forever):
1 2 3 4
+---+---+---+---+---
1| 1 | 2 | 3 | 4 |...
+---+---+---+---+---
2| 2 | 4 | 6 | 8 |...
+---+---+---+---+---
3| 3 | 6 | 9 | 12|...
+---+---+---+---+---
4| 4 | 8 | 12| 16|...
+---+---+---+---+---
|...|...|...|...|...
Find three of the same number in a straight line somewhere within the table. If this is not possible, show why not.
(In reply to
re: Getting less rigorous (spoiler) by Jyqm)
Thanks jqym, right you are.
In fact, now that you mention it, I notice that a straight line can cross three boxes that have
8's also. As previous noted, it doesn't go through all three of their
centers.