the volume of a gas at 0 degree C and 700mm Pressure is 760 cc. the no. of molecules present in this volume is___?

Use the formula PV= nRT
​P = 700 mm Hg = 0.921 atm
V = 760 cc = 0.76 L
R = 0.0821 L atm K^-1 mol^-1
​T = 0º​ C = 273 K
Now putting the values we get :
n = PV/RT
  = ​0.921 atm x ​0.76 L / 0.0821 L atm K^-1 mol^-1 x 273 K​
  = 0.0312 moles
Number of molecules = 0.0312 moles​ x 6.023 x 10²³
                                  = 1.9 x 10²² molecules