The sum of the even numbers between 1 and n is 85*86, where n is an odd number, then n=?	Choose the correct choice from the following answers
A) 163 B) 171 C) 179 D) 185 E) 191
Let n-1 = 2a.   2+4+...+2a = 2*(1+2+...+a) = 2*(a)(a+1)/2 = (a)(a+1) = 85*86   Then a = 85 and n = 171.   The answer is 171.
<result>B</result>
The sum of the even numbers between 1 and n is 85*86, where n is an odd number, then n=?