A bag contains 2 pink marbles, 4 black marbles, 5 blue marbles, 3 red marbles, and 3 orange marbles. If 3 marbles are selected, what is the probability of picking 3 orange marbles?

There are LaTeX: \displaystyle C(17,3)=680 to select 3 marbles. There are LaTeX: \displaystyle 1 ways to select 3 orange from 3 orange. This gives the probability LaTeX: \displaystyle \frac{1}{680}