Surrounding and system change are the same
There is no boundary between the system and the surrounding
Surrounding is always in equilibrium with the system
System changes into the surrounding spontaneously.
Solution:A reversible process is one that follows a reversible path or occurs an infinite number of times in such a way that equilibrium conditions are maintained at each stage and may be reversed by an infinitesimal change in the state of functions. When the surroundings are constantly in equilibrium with the system, a process is called reversible in thermodynamics.