Suppose u. s. drivers purchased $7070 billion of exxonmobil-produced gasoline during a recent year, with one-half purchased directly from exxonmobil-owned gas stations and one-half from independent (or third-party) gas stations. suppose further that exxonmobil purchased the oil (which it refined into gasoline) from foreign producers for $2424 billion and that it receives 60 percent of the sales revenue that independent stations generate from selling exxonmobil gasoline.