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2005 AMC 10A Problem 21

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2005 AMC 10A Problem 21AMC 10 Step by Step
Name:                             Date: September 13, 2026
Divisibility & Factors · difficulty 3 of 5 · about 3 min · position P21-25

For how many positive integers nn does 1+2+⋯+n1+2+\dotsb+n evenly divide 6n6n ?

  1. A)

    33

  2. B)

    55

  3. C)

    77

  4. D)

    99

  5. E)

    1111

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