+136 Find the number of ways of choosing three circles below, so that no two circles are next to each other.
+42 This solution assumes diagonals don't count as being next to each other.
There are three possible circles to choose from in the first row, there are two possible circles to choose from in the second row (because we chose one from the first row), and there is one possible circle to choose from in the third row. Therefore, there are 3*2=6 different ways.
Feel free to tell me if I did anything wrong! :D
