A bag of potato chips contains 595 mL of air at 30.0 ∘C and a pressure of 770 mmHg.?

PV=nRT <<<memorize!!

n is moles, R is gas constant (use correct one!), T is temp in K (C+273.15)

Since you have a before and after with the same n &R simplifies to

PV/T initial = nR = PV/T final

Now sub in your numbers and solve

SI Units R values:

8.31446261815324 J⋅K−1⋅mol−1

8.31446261815324 m3⋅Pa⋅K−1⋅mol−1

8.31446261815324 kg⋅m2·K−1⋅mol−1s−2

8.31446261815324×103 L⋅Pa⋅K−1⋅mol−1

8.31446261815324×10−2 L⋅bar⋅K−1⋅mol−1

0.082057 L atm mol-1K-1

62.36L·torr/mol·K = L·mmHg/mol·K

The temperature goes from 303.15 K to 283.15 K. So the volume factor is

(283.15 / 303.150 ) * (770 / 433) = 1.6610

The new volume is 595 mL * 1.6610 = 988 mL

ADDED: you don't need the value of the gas constant. You just need to know that it is constant, as long as the gas remains a gas. And then that gas volume is proportional to the absolute temperature, and inverse to the pressure.