Consider a town in which only two residents, Daniel and Gabrielle, own wells that produce water safe for drinking. Daniel and Gabrielle can pump and sell as much water as they want at no cost$.$ For them, total revenue equals profit. The following table shows the town's demand schedule for water.

$\backslash$table$[[\backslash$table$[[$Price$],[($Dollars per gallon$)]],\backslash$table$[[$Quantity Demanded$],[($Gallons of water$)]],\backslash$table$[[$Total Revenue$],[($Dollars$)]]],[4\mathrm{.}80,0,0],[4\mathrm{.}40,35,$$$154\mathrm{.}00$