Question 414395
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Hi
{2,4,6,8,10,...,1020} is an Arithmetic Sequence where difference between the terms = 2
{{{a[n]=a[1]+(n-1)*d}}}
   1020=2+(n-1)*2
    1018/2 = n-1
     509 + 1 = n
        510 = n   (1020 is the 510 term)  Note: 1020/2 = 510
{{{S[n]=(n/2)(2*a[1]+ (n-1)d)}}}
{{{S[510]=(510/2)(2*2+ (509)2)}}} = 255(1022) = 260,610