2). For a MUTEX m, we use Lock(m) and Unlock(m) to interact.

This is frequently used to implement a critical section: Lock(m). Critical Code. Unlock(m).

We believe this solution to be sufficient. But, what happen in the extremely unlucky case that two processes arrive at exactly & precisely the same moment. This is not likely, but probabilistically can happen from time to time. Even more coincidentally, lets assume the lock is OPEN so that both processes would find the lock available. What happens?