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2005 AMC 10B Problem 22

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2005 AMC 10B Problem 22AMC 10 Step by Step
Name:                             Date: September 13, 2026
Divisibility & Factors · difficulty 4 of 5 · about 6 min · position P21-25

For how many positive integers nn less than or equal to 2424 is n!n! evenly divisible by 1+2+⋯+n?1 + 2 + \cdots + n?

  1. A)

    88

  2. B)

    1212

  3. C)

    1616

  4. D)

    1717

  5. E)

    2121

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