If two systems are separated by a diathermic wall, the macroscopic quantity which is equal for two systems is:

Two samples $A$ and $B$ initially kept at the same state. They are taken through different thermodynamic process to same final volume. Sample $A$ is expanded through an adiabatic process and the sample $B$ through an isothermal process. What will be their final pressures? ($p_{A }$and $p_B$ are the final pressures of $A$ and $B$ respectively)

A system $\mathrm{X}$ is neither in thermal equilibrium with $\mathrm{Y}$ nor with $\mathrm{Z}$. The systems $\mathrm{Y}$ and $\mathrm{Z}$: