TED-Ed: Can you solve the locker riddle? - Lisa Winer

The video tutorial presents a riddle left by an eccentric uncle in his will. The challenge involves 100 lockers, each assigned to a relative. The task is to determine which lockers remain open after a sequence of opening and closing actions based on the number of factors each locker number has. The solution reveals that only lockers with an odd number of factors, which are perfect squares, remain open. The code to the safe is derived from the first five prime-numbered lockers, allowing the protagonist to claim the inheritance.

What new insight or understanding did you gain from this video?