To determine the price per gallon we need to divide the cost by the number of gallons.
For Brans A we have:
[tex]C_A=\frac{5.28\text{ dollar}}{2\text{ gallon}}=2.64\text{ dollar/gallon}[/tex]For Brand B:
[tex]C_B=\frac{10.4\text{ dollar}}{4\text{ gallon}}=2.6\text{ dollar/gallon}[/tex]The better price is for Brand B since:
[tex]2.6<2.64[/tex]The difference is:
[tex]2.64-2.6=0.04[/tex]