Question 481469
  <pre><font face = "Tohoma" size = 4 color = "indigo"><b> 
Hi,
arithmetic series 100 + 102 + 104...+248 + 250, d = 2
{{{a[n]=a[1]+(n-1)*d}}}
{{{250= 100+(n-1)*2}}}
    150/2 + 1 = n
         76 = n
{{{S[n] =(n/2)(a[1] + a[n])}}}
{{{S[76] =(76/2)(100 + 250) = 76*350/2)= 13,300}}}