Question 1130612: How many 4-digit even numbers that are between 3000 and 7000 can be made? What is their sum?
Found 2 solutions by rothauserc, MathTherapy:
Answer by rothauserc(4718)   (Show Source):
You can put this solution on YOUR website! 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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Answer by MathTherapy(10549)  (Show Source):
You can put this solution on YOUR website!
How many 4-digit even numbers that are between 3000 and 7000 can be made? What is their sum?
You didn't say "from 3,000 to 7,000," but BETWEEN 3,000 and 7,000. Therefore, the 4-digit even numbers you refer to begin at 3,002 and end at 6,998.
This is a total of 
Use that fact to find the sum of these 1,999 4-digit even numbers.
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