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This wording means that there are 7 equal groups of tourists and 8 equal groups of locals of the same cardinality.
From given data, we find the cardinality momentarily: it is = 30.
So, each group of tourists contains 30 persons, same as each group of locals consists of 30 persons.
As soon as you know it, you get the ANSWER in the next instance: the number of locals is 8*30 = 240.
Solved.
Good problem for 3rd grade young students, who are just able to divide and to multiply
integer numbers mentally in their minds.