Let S = 1 + 2 + 3 + ... + 2010. What is the residue of S, modulo 2010?
the sum can be expressed as 2011 * 1005. Then, we know that 2010 * 1005 is a multiple of 2010. adding 1005 onto that then it is 2011 * 1005, which is S. I am not familiar with residues, but I do knowk that S mod 2010 = 1005 hope this helps
+137 
