A chemist, an engineer and an economist were stranded on a deserted island.
They found some canned food but have nothing obviously useful for opening the cans.
The chemist suggested gathering some wood and starting a fire and then holding the cans over the heat, counting on the expanding contents to burst open the cans.
The engineer thought it would be better to try smashing the cans open with some of the rocks lying around.
The economist said, “Assume we had a can opener…”