3x5 and 2x4 Plates
You have two Lego plates; one is a 3x5 plate and one is a 2x4 plate. You start with the 3x5 plate flat on the table in front of you. How many different ways can you position the 2x4 plate on top of the 3x5 plate, so it is connected by at least one stud?
This problem is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.