Which is why if you commit to doing a take home project, you should at least ask how much time they expect the project to take. For a lot of software development projects there is always something to work on and improve if time allows. Parkinsons Law and all. I might be a good idea to exceed their estimate a little to get a more finished product, but that number at least anchors the project timeline. If they legitimately answer with 50 hours, then feel free to laugh in their face. However a 2 or 3 hour project to be completed at some point over 2 weeks seems completely reasonable.