Abby, kim, bob, and christine will run together as a team in a relay race. how many orders of the 4 runners are possible?

4 x 3 x 2 x 1

In the first spot, there are 4 possible runners. Once that runner is selected, there are 3 people left to pick from for the second spot, and so on so that the third spot has two possible people, and the fourth spot can only have one person. 

There are 24 possible orders for the runners.