John and Paul are stranded on a deserted island where they survive by catching fish and picking coconuts. In one day John can catch 5 fish OR pick 15 coconuts or he can divide his time between the two in any way with no loss of efficiency. Similarly, Paul can catch 20 fish or pick 16 coconuts in a day (and also divide time in any way between the two).

Absolute advantage in fish:

Absolute advantage in coconuts:

Comparative advantage in fish:

Comparative advantage in coconuts: