Solution: Since the kiosks are arranged in a circle and rotations are considered the same, we fix one session to eliminate rotational symmetry. First, assign 4 out of 7 kiosks to the sessions: $inom{7}{4} \cdot 4!$ would count linear arrangements. But due to circular symmetry, we divide by 4 (the number of rotations).

Wed, 15 Apr 2026 22:27:52 +0000

Content under review