An ice cream parlour has 8 flavours of ice cream. Joyce wants a cone with 3 different scoops. She wants chocolate mint on the top. How many different ways can she choose the other 2 flavours?
Since the top scoop is already defined, we only deal with the middle and bottom scoop.
For the bottom scoop she has
For the middle scoop she has
This is a total of
If the order doen't matter, then every of the above choices has a double in reversed order. So the number of combinations is: