Chapter 9.2, Problem 51E

Transportation. Most railroad cars are owned by individual railroad companies. When a car leaves its home railroad’s tracks, it becomes part of a national pool of cars and can be used by other railroads. The rules governing the use of these pooled cars are designed to eventually return the car to the home tracks. A particular railroad found that each month, $11\%$ of its boxcars on the home tracks left to join the national pool, and $29\%$ of its boxcars in the national pool were returned to the home tracks. If these percentages remain valid for a long period of time, what percentage of its boxcars can this railroad expect to have on its home tracks in the long run?