<PRE><B>Question 1130612</B>
7000 - 3000 = 4000
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4000/2 = 2000+1 = 2001 even numbers
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Note between 10 and 20 there are 6 even numbers
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for this problem, n=2001, d=2, a(1)=3000, a(n)=7000
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S(n) = n(a(1) +a(n))/2
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S(2001) = 2001 * (3000 + 7000) / 2 = 10,005,000
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