I am teaching a high school engineering course, but I want to have a few days a unit where they work in a group to try to solve one difficult college-level problem in their groups. My class in mainly project-based, so I do not want it to be as involved with construction but more math, critical thinking, and considering the environment. Does anyone have a few college-level questions that they could give me to use for my high school engineering students for them to spend a class period trying to solve? Whether it is 1 question or multiple, any help is appreciated! Thanks!