Two insulated vessels hold the same ideal monatomic gas. Vessel A has a volume of $2\ \text{L}$, at a pressure of $3\ \text{atm}$ and a temperature of $300\ \text{K}$. Vessel B has a volume of $3\ \text{L}$, at $2\ \text{atm}$ and $400\ \text{K}$. The vessels are joined by a thin insulated tube with a valve, and the valve is opened. When everything has settled, the common pressure and temperature are