2006 AMC 12B Problems/Problem 7
Problem
Mr. and Mrs. Lopez have two children. When they get into their family car, two people sit in the front, and the other two sit in the back. Either Mr. Lopez or Mrs. Lopez must sit in the driver's seat. How many seating arrangements are possible?
Solution
First, we seat the children.
The first child can be seated in 3 spaces.
The second child can be seated in 2 spaces.
Now there are 2*1 ways to seat the adults.