an average of 10 cars waits in line. The manager wants to determine if the length of the line impacts on potential sales. Her study reveals that, on average, 2 cars per minute try to enter the drive-through area, but 25% of these cars are dismayed by the long line and simply move on without entering the line and placing orders. Assume that no car entering the line leaves without service. On average, how long does a car spend in the drive-through line