Iron Has a Density of 7

Iron has a density of 7.87 g/cm³.What mass of iron would be required to cover a football playing surface of 120 yds × 60 yds to a depth of 1.0 mm? (1 inch = 2.54 cm; 1 lb = 453.6 g)

A) 6.4 × 10³ lb
B) 6.4 × 10⁴ lb
C) 1.0 × 10⁵ lb
D) 4.7 × 10⁷ lb
E) 4.7 × 10⁸ lb