Difference between revisions of "2002 AMC 10B Problems/Problem 3"

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We wish to find <math>\frac{9+99+\cdots +999999999}{9}</math>, or <math>\frac{9(1+11+111+\cdots +111111111)}{9}=123456789</math>. This does not have the digit 0, so <math>\mathrm{ (A) \ }</math>
 
We wish to find <math>\frac{9+99+\cdots +999999999}{9}</math>, or <math>\frac{9(1+11+111+\cdots +111111111)}{9}=123456789</math>. This does not have the digit 0, so <math>\mathrm{ (A) \ }</math>
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==See Also==
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{{AMC10 box|year=2002|ab=B|num-b=2|num-a=4}}
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[[Category:Introductory Algebra Problems]]

Revision as of 12:57, 27 December 2008

Problem

The arithmetic mean of the nine numbers in the set $\{9,99,999,9999,...,999999999\}$ is a $9$-digit number $M$, all of whose digits are distinct. The number $M$ does not contain the digit

$\mathrm{(A) \ } 0\qquad \mathrm{(B) \ } 2\qquad \mathrm{(C) \ } 4\qquad \mathrm{(D) \ } 6\qquad \mathrm{(E) \ } 8$

Solution

We wish to find $\frac{9+99+\cdots +999999999}{9}$, or $\frac{9(1+11+111+\cdots +111111111)}{9}=123456789$. This does not have the digit 0, so $\mathrm{ (A) \ }$

See Also

2002 AMC 10B (ProblemsAnswer KeyResources)
Preceded by
Problem 2
Followed by
Problem 4
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 10 Problems and Solutions