[names_are_hard]

I heard a variation of this that ended with the mathematician scribbling the same equations as the physicist and then stating "and this the problem reduces to a previously solved problem" and going back to sleep without bothering to open the can.

Instead of a can of soup it was a fire that broke out in their respective rooms, the engineer sprays fire extinguisher all over the room, the physicist sprays precisely at the exact point that will extinguish the fire, and the mathematician is satisfied knowing that the problem has a known solution.