Problem #25

Given the set of natural numbers, {1, 2, 3, 4,…}, find the 2010th number in this set that is not divisible by 2 or 3.

One Response to Problem #25

  1. Let S be the set of natural numbers not divisible by 2 or 3.

    Then all x \in S must be congruent to either 1 or 5, modulo 6.

    Hence the 2010th smallest member of S must be (2010/2)\cdot 6 - 1 = 6029.

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