Difference between revisions of "1991 AHSME Problems/Problem 1"
(Added solution and changed format of answer choices.) |
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| + | ==Problem== | ||
If for any three distinct numbers <math>a</math>, <math>b</math>, and <math>c</math> we define <math>f(a,b,c)=\frac{c+a}{c-b}</math>, then <math>f(1,-2,-3)</math> is | If for any three distinct numbers <math>a</math>, <math>b</math>, and <math>c</math> we define <math>f(a,b,c)=\frac{c+a}{c-b}</math>, then <math>f(1,-2,-3)</math> is | ||
| − | (A) | + | <math> \textbf {(A) } -2 \qquad \textbf {(B) } -\frac{2}{5} \qquad \textbf {(C) } -\frac{1}{4} \qquad \textbf {(D) } \frac{2}{5} \qquad \textbf {(E) } 2 </math> |
| + | |||
| + | ==Solution== | ||
| + | If we plug in <math>1</math> as <math>a</math>, <math>-2</math> as <math>b</math>, and <math>-3</math> as <math>c</math> in the expression <math>\frac{c+a}{c-b}</math>, then we get <math>\frac{-3+1}{-3-(-2)}=\frac{-2}{-1}=2</math>, which is choice <math>\boxed{\textbf{A}}</math>. | ||
{{MAA Notice}} | {{MAA Notice}} | ||
Revision as of 13:51, 22 July 2014
Problem
If for any three distinct numbers 
, 
, and 
we define 
, then 
is
Solution
If we plug in 
as , 
as , and 
as in the expression 
, then we get 
, which is choice 
.
The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. 
