Difference between revisions of "2003 AMC 12A Problems/Problem 1"

Revision as of 23:07, 27 April 2011

What is the Difference between the sum of the first $2003$ even counting numbers and the sum of the first $2003$ odd counting numbers?

$\mathrm{(A) \ } 0\qquad \mathrm{(B) \ } 1\qquad \mathrm{(C) \ } 2\qquad \mathrm{(D) \ } 2003\qquad \mathrm{(E) \ } 4006$

The first $2003$ even counting numbers are $2,4,6,...,4006$ .

The first $2003$ odd counting numbers are $1,3,5,...,4005$ .

Thus, the problem is asking for the value of $(2+4+6+...+4006)-(1+3+5+...+4005)$ .

$(2+4+6+...+4006)-(1+3+5+...+4005) = (2-1)+(4-3)+(6-5)+...+(4006-4005)$

$= 1+1+1+...+1 = 2003 \Rightarrow D$

2003 AMC 12 (Problems • Answer Key • Resources)
Preceded by First Question	Followed by Problem 2
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25
All AMC 12 Problems and Solutions

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 *[[2003 AMC 12A Problems]]
-*[[2003 AMC 12A/Problem 2|Next Problem]]
+{{AMC12 box|year=2003|before=First<br />Question|num-a=2}}
 [[Category:Introductory Algebra Problems]]