Divide the 10x10 square in ten
different,
distinct rectangles so that each one has a dot at a corner.
+---+---+---+---+---+---+---+---+---+---+
| | | | | | | | | | |
+---+---+---+---+---+---+---+---+---+---+
| | O | | | | | O | | | |
+---+---+---+---+---+---+---+---+---+---+
| | | | | | | | | | |
+---+---+---+---+---+---+---+---+---+---+
| | | | | | O | | | | |
+---+---+---+---+---+---+---+---+---+---+
| | | O | | | | | | | |
+---+---+---+---+---+---+---+---+---+---+
| | | | | | | | | | |
+---+---+---+---+---+---+---+---+---+---+
| | | | | | | | | | O |
+---+---+---+---+---+---+---+---+---+---+
| | | | O | | | O | | | |
+---+---+---+---+---+---+---+---+---+---+
| | | | | | | | O | | |
+---+---+---+---+---+---+---+---+---+---+
| | | | | | | O | O | | |
+---+---+---+---+---+---+---+---+---+---+