In The Can

An engineer, a rabbi and an economist are stranded on a desert island. They find a single can of tuna fish washed up on the beach, but they have no can opener.

The engineer tries to calculate the amount of force and torque necessary to open the can by throwing it on a rock.

The rabbi prays to God for help in figuring out how to open the can.

The economist says, "This is no problem. Assume a can opener..."