2. Select the conversions that are equivalent to 10 yards.
2 answers:
You might be interested in
Notice that
2010 ≡ 1 mod 2009
2011 ≡ 2 mod 2009
2012 ≡ 3 mod 2009
...
4017 ≡ 2008 mod 2009
4018 ≡ 0 mod 2009
So really, <em>S</em> is just the sum of the first 2008 positive integers:
where we invoke the formula
and so <em>S</em> ≡ 0 mod 2009.