An ideal gas piston o
:i 2q(vk g-r+ln/peiya)w3xmz6 bl t0f 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?