Question 1151886
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In accurate mathematical formulation, the question is



    In the set of integer numbers from 1 to 1000, how many integers are multiples of 75 and 90, simultaneously ?



The least common multiple of the numbers  75 = 15*5  and  90 = 15*6  is  15*5*6 = 450,

so there are exactly 2 such numbers, 450 and 900.
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