If two quantities (V , P) are in inverse proportion, so

You can use one of these two rules to solve your question
K is the constant of variation, you can find it by using the initial values
Let us use the second rule
When V = 270 cubic inches, P = 6 pounds/square inch
We need to find V = ?, P = 7 pounds/square inch
By using the second rule

By using cross multiplication

Divide both sides by 7

Round the answer to the nearest integers

The volume of the gas is 231 cubic inches