What happens if water vapour at a pressure of 0.003 atmosphere is cooled to `0^(@)C`?

Explanation

The pressure corresponding to triple point of water is 0.46 cm of Hg (=0.006 atm). From the study of P-T phase diagram, we note that at a pressure lower than 0.006 atm. Water vapour condenses directly into ice. As the given water vapour is at a pressure 0.003 atm. which is less than the pressure of triple point of water, hence, these water vapours condense directly into ice.