A petroleum refinery has two crude oil feeds available. The first crude $($Crude $1)$ is high$-$

quality feed and costs $$30$ per barrel $(1$ bbl $=42$ US gallons$).$ The second crude $($Crude $2)$

is a low$-$quality feed and costs $$20$ per barrel. The crude oil is separated into gasoline,

diesel, jet fuel and fuel oil. The percent yield of each of these products that can be

obtained from Cru