Question 526679

The expression "303(g)" means 3.03 multiplied by g. The parentheses were not really necessary, and may be confusing you, but it is not a trick question.
The number 3.03 is what you multiply the number of gallons of gas purchased to find the price you have to pay. It is obviously the price of a gallon of gas.
C(2) is the cost of 2 gallons of gas 2 multiplied by 3.03.