2017 AMC 10B Problems/Problem 20

Revision as of 12:15, 16 February 2017 by Thedoge (talk | contribs) (Solution)

Problem

Placeholder

Solution

We note that the only thing that affects the parity of the factor are the powers of 2. Since there are $10+5+2+1 = 18$ factors of 2, and since only haveing a 0 power of 2 makes the factor odd, then the answer is $\boxed{\textbf{(B) } \frac 1{19}}$.

See Also

2017 AMC 10B (ProblemsAnswer KeyResources)
Preceded by
Problem 19
Followed by
Problem 21
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All AMC 10 Problems and Solutions

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