2009 UNCO Math Contest II Problems/Problem 2

Revision as of 21:13, 19 October 2014 by Timneh (talk | contribs) (moved 2009 UNC Math Contest II Problems/Problem 2 to 2009 UNCO Math Contest II Problems/Problem 2: disambiguation of University of Northern Colorado with University of North Carolina)

Problem

(a) Let $Q_n=1^n+2^n$. For how many $n$ between $1$ and $100$ inclusive is $Q_n$ a multiple of $5$?

(b) For how many $n$ between $1$ and $100$ inclusive is $R_n=1^n+2^n+3^n+4^n$ a multiple of 5?


Solution

See also

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