Question

A system X is neither in thermal equilibrium with Y nor with Z. The systems Y and Z
(a) must be in thermal equilibrium
(b) cannot be in thermal equilibrium
(c) may be in thermal equilibrium

Answer 1

(c) may be in thermal equilibrium

The given data in the question is insufficient to specify the relation between the physical conditions of systems Y and Z. As system X is not in thermal equilibrium with Y and Z, systems Y and Z may be at the same temperature or they may or may not be in thermal equilibrium with each other. So, the only possible option is (c).