Question 14034
You can use the formula for the partial sum:

{{{S = (n/2)(a1 + an)}}}
 Where: n = the number of terms = 2500 (because there are 2500 odd integers between 1 and 5000)
a1 = the first term (That's 1)
an = the last (odd) term (That's 4999)

{{{S = (2500/2)(1+4999)}}}
{{{S = (2500/2)(5000)}}}
{{{S = 6250000}}}