If a 10. m3 volume of air (acting as an ideal gas) is at a pressure of 760 mm and a temperature of 27 degrees celsius is taken to a high altitude where the pressure is 400. mm hg and a temperature of -23 degrees celsius, what volume will it occupy? (hint: remember the temperature must be in kelvin)

From the combined gas law
P1V1/T1 = P2V2/T2, Where P1, V1 and T1 are the initial pressure, volume and temperature respectively, while P2,V2 and T1 are the new pressure, volume and temperatures respectively.
Thus; P1= 760 mmHg, V1=10 m^3, T1 = 27 +273 = 300 K
P2= 400 mmHg, V2= ? and T2= -23 +273 = 250K
V2 = (P1V1T2)/T1P2
      = (760×10×250)/(300×400)
      =  1900000/120000
      = 15.83 
Therefore, the new volume is 15.83 m³

Where’s the stuff st? ? lol sorry