Solution: Each of the 4 volcanoes independently exhibits one of 3 eruption intensities: low, medium, or high. Since the volcanoes are distinguishable (due to different locations), but the eruption *profile* (i.e., the multiset of intensities) only considers counts of each type, and the volcanoes are distinguishable, we are counting the number of 4-tuples where each element is from a 3-element set (low, medium, high), and the order does **not** matter in terms of labeling—wait, correction: since each volcano is a distinct entity (e.g., monitored individually), the classification is based on assigning an intensity to each volcano, and even though eruptive profiles are unordered in reporting, the underlying assignment to specific volcanoes **is** tracked. Therefore, we are counting **functional mappings** from 4 distinguishable volcanoes to 3 intensity categories, **with repetition allowed**, and **order of assignment does not affect group counts**—but since volcanoes are distinguishable, each different assignment is unique unless specified otherwise.

Thu, 16 Apr 2026 07:45:55 +0000

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