An ideal gas piston of total volume
u, ( q/0/i8tb-ufggh9szsrmu2c4- h u8 fpfvd $3900\,cm^3$ contains $3600\,cm^3$ of air and $3300\,cm^3$ of water at a temperature of $27^{\circ}C$. The system is cooled and the piston contracts at constant pressure.
What is the approximate total piston volume at the point where the water first starts to freeze?