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Ali, Bonnie, Carlo, and Dianna are going to drive together to a nearby theme park. The car they are using has 4 seats: 1 Driver seat, 1 front passenger seat, and 2 back passenger seat. Bonnie and Carlo are the only ones who know how to drive the car. How many possible seating arrangements are there? (2003 AMC 8 Problem, Question \#16) 
Overseas Competition->Knowledge Point->Counting Modules->Statistics and Probability
There are only 2 people who can go in the driver\textquotesingle s seat-Bonnie and Carlo. Any of the 3 remaining people can go in the front passenger seat. There are 2 people who can go in the first back passenger seat, and the remaining person must go in the last seat. Thus, there are $2 \cdot 3 \cdot 2$ or 12 ways. The answer is then (D) 12 . 