Here's the idea: 1 apartment, 4 appliances, 4 utilities: connect each appliance to its utility, but you may not have one utility line cross another, and the lines may not leave the apartment or go through another appliance. You can download the "preview" file to your hearts' content and share it with your kiddies.
HOWEVER! If you want the solution, well, that's going to cost you, and cost you BIG TIME! That is, if you consider $3.01 big time.... Not only do you get the solution, but you get a wonderful printable that connects this problem to a 19th century Swiss mathematician and the development of the computer chip over a century later.
You'll love it!