Please someone can help with this answer?

6,000kg/m3

Explanation:

6.00g/1cm3 x 1kg/1000g x 1cm3/0.000001m3

= 6.00kg/0.001m3

= 6,000kg/m3

At S.T.P  the  molar volume of a gas  is  22.4L,that  is 1mol=22.4l therefore  the  voume  of  1.2 moles  of water   vapor is
1.2 x22.4=26.7L

   alternatively
from  ideal gas  law v=nRT /P
At  S.T.P the  temperature  is 273k  and pressure is  1atm
R=0.0831 atm/mol/k
v=(1.2  x 0.0821 x273)/(1am)=26.8L