Art of Problem Solving

2005 AMC 12B Problems/Problem 17: Difference between revisions

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== Problem ==
== Problem ==
How many distinct four-tuples <math>(a,b,c,d)</math> of rational numbers are there with
<cmath>a\cdot\log_{10}2+b\cdot\log_{10}3+c\cdot\log_{10}5+d\cdot\log_{10}7=2005?</cmath>
<math>
\mathrm{(A)}\ 0      \qquad
\mathrm{(B)}\ 1      \qquad
\mathrm{(C)}\ 17    \qquad
\mathrm{(D)}\ 2004  \qquad
\mathrm{(E)}\ \text{infinitely many}
</math>


== Solution ==
== Solution ==

Revision as of 17:18, 21 February 2010

Problem

How many distinct four-tuples $(a,b,c,d)$ of rational numbers are there with

\[a\cdot\log_{10}2+b\cdot\log_{10}3+c\cdot\log_{10}5+d\cdot\log_{10}7=2005?\]

$\mathrm{(A)}\ 0      \qquad \mathrm{(B)}\ 1      \qquad \mathrm{(C)}\ 17     \qquad \mathrm{(D)}\ 2004   \qquad \mathrm{(E)}\ \text{infinitely many}$

Solution

See also