Statistically, if they geolocate you once per 24h, they will find you either at home or at work. Once both locations are known, determining which is which does not strike me as very hard.
Yeap. When I got my first android phone Google needed one roundtrip to determine where I live and work.
But their only method of location is IP, with the last octet removed. No way that's accurate enough to identify your home and work location.
If you are working in any bigger company they have more than a C class, so they can identify company. If you go there frequently you are employee. You can infer how often /24 changes, means you are traveling or even commuting between work and home. You can't infer exact location but some close area can be guessed. They have a set of data for bigger group so they can create highly probable guesses what people may be doing and where they are.