Answer
$0.06 dollars$
Work Step by Step
Given the threshold limit and the volume of the aircraft hangar, we can find the amount needed. Since there is a difference in units, we need to convert cubic ft into L. We then multiply the amount with the cost per gram, giving 0.06 dollars as the final answer.
$5.0x10^{7} ft^{3}\times \frac{(30.48 cm)^{3}}{1 ft^{3}} \times \frac{1 L}{1000 cm^{3}} \times\frac{2.0x10x^{-11}g}{L} \times\frac{112 dollars}{50 g} = 0.06 dollars$