combinatorics and probability

Question

SEVEN DISTINCT POINTS ARE DRAWN ON A CIRCLE. HOW MANY DIFFERENT TRIANGLES CAN BE DRAWN IN WHICH EACH VERTEX OF THE TRIANGLE IS AT 1 OF THE 7 POINTS?

Answer 1

This sounds fairly simple...just look for # of distinct combinations using 3 points, from the 7 available, so answer is ₇C_3.