Difference between revisions of "1991 AJHSME Problems/Problem 11"
5849206328x (talk | contribs) (Created page with '==Problem== There are several sets of three different numbers whose sum is <math>15</math> which can be chosen from <math>\{ 1,2,3,4,5,6,7,8,9 \} </math>. How many of these set…') |
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[[Category:Introductory Algebra Problems]] | [[Category:Introductory Algebra Problems]] | ||
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Latest revision as of 23:07, 4 July 2013
Problem
There are several sets of three different numbers whose sum is 
which can be chosen from 
. How many of these sets contain a 
?
Solution
Let the three-element set be 
and suppose that 
.
We need 
and 
. This gives us four solutions, so there are 
sets with a also with the desired properties 
.
See Also
| 1991 AJHSME (Problems • Answer Key • Resources) | ||
| Preceded by Problem 10 |
Followed by Problem 12 | |
| 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 AJHSME/AMC 8 Problems and Solutions | ||
The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. 
