I think that it is about 20 out of 100.
Answer:

Step-by-step explanation:
So, for 60 square feet they charge = 287
So, for 1 square foot they charge = 
If they charge the installation fee this becomes = 
We can write an equation to calculate cost by using this 
Where x is the amount of square foot
This is not answer but Photomath is really helpful and it shows you step by step on how to solve it as well
We first assume that this gas is an ideal gas and we use the ideal gas equation to determine the answer. It is expressed as:
PV = nRT
Molar volume can be obtained from the equation by V/n.
V/n = RT/P
Therefore, the correct answer from the choices listed above is option A, <span>at 273 K and at 2.0 atm.</span>