At the drive- through counter of a fast- food outlet, an average of 10 cars waits in line. The manager wants to determine if the length of the line is having any impact on potential sales. A study reveals that, on average, 2 cars per minute try to enter the drive-through area, but 25 percent of the drivers of these cars are dismayed by the long line and simply move on without placing orders. Assume that no car that enters the line leaves without service. On average, how long does a car spend in the drive- through line?