Tell whether each situation is a permutation or combination.
Twelve points are marked on a circle. How many different line segments can be drawn between any two of the points?
and we want to connect points on the circle. So connecting a to B is the same as if I connect be to a eso. The order is an important that makes this a combination of 12 choose to which is 12 times 11 over two times one, which is 132 over two, which means there are 66 ways to be that.