"Isooctane", a Fuel Used in Gasoline Engines Because It Has

"Isooctane", a fuel used in gasoline engines because it has an antiknock octane rating of 100, has a density of 0.6919 g/cm³. How many pounds would 20.4 gallons of this fuel (a typical full tank) weigh? 1 gallon = 3785 cm³ = 4 quart; 1 pound = 453.6 g

A) 77.2 pounds
B) 246 pounds
C) 118 pounds
D) 24.2 pounds
E) 50.6 pounds