Equal groups followed by a change

A class sets out five trays with six counters on each tray. After counting the starting collection, three counters are removed for another activity. A learner multiplies five by six and reports thirty as the final answer. Another subtracts three from six before multiplying, as though three counters had been removed from every tray. A third draws five equal groups, counts thirty and then removes just the stated three. The task asks how many counters remain and why the model matches the story. All numbers are supplied exercise conditions. There is no hidden tray, missing diagram or additional removal. The explanation should connect each operation to an event and finish with the actual quantity requested, rather than select a calculation merely because familiar numbers appear.