The volume of a gas varies directly with its temperature and inversely with the pressure. If the volume of a certain gas is

20 cubic feet at a temperature of
350K and a pressure of 35
pounds per square inch, what is the volume of the same gas at 330
K when the pressure is 30
pounds per square inch?

2 answers

V = kt/p
for the given data:
20 = k(350)/35
k = 20(35)/350 = 2

V = 2t/p

when t=330, p=30
V = 2(330)/30 = 22
PV=kT, so PV/T=k is constant. o, you need V such that

30V/330 = 35*20/350
V/11 = 2
V = 22