Difference between revisions of "2004 AMC 10A Problems/Problem 2"

(Problem)
Line 1: Line 1:
 
== Problem ==
 
== Problem ==
For any three [[real number]]s <math>a</math>, <math>b</math>, and <math>c</math>, with <math>b\neq c</math>, the [[operation]] <math>\otimes</math> is defined by:
+
For any three real numbers <math>a</math>, <math>b</math>, and <math>c</math>, with <math>b\neq c</math>, the operation <math>\otimes</math> is defined by:
<math>
+
<cmath>\otimes(a,b,c)=\frac{a}{b-c}</cmath>
\otimes(a,b,c)=\frac{a}{b-c}
+
What is <math>\otimes(\otimes(1,2,3),\otimes(2,3,1),\otimes(3,1,2))</math>?
</math>
 
What is <math>\otimes<cmath>( \otimes</cmath>(1,2,3),<cmath>\otimes</cmath>(2,3,1),<cmath>\otimes</cmath>(3,1,2))</math>?
 
  
 
<math> \mathrm{(A) \ } -\frac{1}{2}\qquad \mathrm{(B) \ } -\frac{1}{4} \qquad \mathrm{(C) \ } 0 \qquad \mathrm{(D) \ } \frac{1}{4} \qquad \mathrm{(E) \ } \frac{1}{2} </math>
 
<math> \mathrm{(A) \ } -\frac{1}{2}\qquad \mathrm{(B) \ } -\frac{1}{4} \qquad \mathrm{(C) \ } 0 \qquad \mathrm{(D) \ } \frac{1}{4} \qquad \mathrm{(E) \ } \frac{1}{2} </math>

Revision as of 17:21, 20 July 2014

Problem

For any three real numbers $a$, $b$, and $c$, with $b\neq c$, the operation $\otimes$ is defined by: \[\otimes(a,b,c)=\frac{a}{b-c}\] What is $\otimes(\otimes(1,2,3),\otimes(2,3,1),\otimes(3,1,2))$?

$\mathrm{(A) \ } -\frac{1}{2}\qquad \mathrm{(B) \ } -\frac{1}{4} \qquad \mathrm{(C) \ } 0 \qquad \mathrm{(D) \ } \frac{1}{4} \qquad \mathrm{(E) \ } \frac{1}{2}$

Solution

$\otimes<cmath> \left(\frac{1}{2-3}, \frac{2}{3-1}, \frac{3}{1-2}\right)=</cmath>\otimes$$(-1,1,-3)=\frac{-1}{1+3}=-\frac{1}{4}\Longrightarrow\mathrm{(B)}$

See also

2004 AMC 10A (ProblemsAnswer KeyResources)
Preceded by
Problem 1
Followed by
Problem 3
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

The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. AMC logo.png