An ideal gas piston
pg y *b*nemtrew2w0d b/ o:(s5of total volume $3900\,cm^3$ 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?