Answer:
take 16.03 and subtract 2.9
16.03-2.9=13.13
so maria used 13.13 gallons
Step-by-step explanation:
Maria used 13.13 gallons of gas, because the 16.03 gallons she started with minus the 2.9 gallons she had left equals 13.13 gallons. You can check by adding 2.9+13.13 to equal the 16.03 she started with.