AN ECONOMIST, A CHEMIST, AND A PHYSICIST ARE MAROONED ON A DESERT ISLAND.....

Their only food is a can of beans, but they have no can opener. What do they do? The physicist says: "Let's try and focus the tropical sun onto the lid - it might melt a hole." "No", says the chemist. "We should first pour salt water on the lid - maybe that will rust it." The economist interrupts: "You're wasting your time with all these complicated ideas. Let's just assume a can opener."