I was making a PCB drilling machine at home with my brother, and came across this mathematical? problem. I needed to fix the drill machine. But I needed to determine where should it be fixed so that I could drill largest possible PCB boards. In other words, find the value of x so that you could drill rectangular PCBs of largest possible width. When I say 'could drill PCB', I mean, you need to be able to place every point of the PCB below the drill so as to be able to drill anywhere in the PCB. Ask if I didn't make any sense. The question isn't as simple as it may look. But its not hard enough to deserve to be posted in maths forum. You may think you already know the answer when you really don't. We enjoyed solving this problem, so I shared it here.