I'd be happy to help you out with this one (it's from a Kaplan CAT, if I recgnize it correctly), but I'm not sure what yo're looking for. Do you have a specific question regarding the solution to this problem?

Hey Eli: I'll just go ahead and assume that the original poster wants a solution or wanted to share the problem with other members.

Whenever you are dealing with number line (as well as many coordinate geometry problems for that matter), it is important to think about two factors: distance AND order. People often neglect order. Also, you should visualize the situation, and diagram on your scratchpaper.

(1) gives us info about distance. So, this question, despite the algebraic facade, is really more like a number line question. The key is to not assume that both the airport (AP) and convention center (CC) are both east (or both west or both north or both south) of the city. That is, you can't assume that the order is city--CC--AP. It could be CC--city--AP. For example, the convention center can lie 3 miles west of the city, while the airport is 3 miles east of the city. And because the total distance separating the airport and convention center is 11 miles, this would make the distance the car travels through the city 5 miles. Because we don't know how many in-city and out-city miles there are, we can't compute the total cost of the ride from (1). (2) doesn't give us this information either. Together, we still don't know. Choose E.

Thanks testluv, I was looking for a better and detailed explanation since I was not satisfied with the KAPLAN explanation..

Thanks for the detailed explanation..