We can calculate the percent of the price that is excise tax by dividing the amount of tax per gallon by the final price of the gallon.
If the tax is 0.16 per gallon and the final price is 1.25 per gallon, the percentage can be calculated as:
[tex]p=\frac{0.16}{1.25}\cdot100\text{ \%}=0.128\cdot100\text{ \%}=12.8\text{ \%}[/tex]The percentage that is city excise tax is 12.8% of the final price of the gasoline.