The most common size of a sedan tank is 18.5 gallons. So if it is 75% full, it contains 13.875 gallons of gas. If it recorded a mileage of 15,121 miles, mileage per gallon, therefore, is 1090 rounded off to the nearest whole number.
Given: Gas full tank of a sedan – 18.5 gallons
75% full = 13.875 gallons
Mileage using 13.875 gallons of fuel = 15,121 miles
The mileage per gallon computation using the ratio equation:
Ratio is 15121:13.875 or
X/1= 15121/13.875
13.875x = 15121
X = 15121/13.875
X =1089.80 or 1090 miles per gallon (rounded off)
