Difference between revisions of "2009 UNCO Math Contest II Problems/Problem 10"
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== Solution == | == Solution == | ||
| + | (a) <math>133</math> | ||
| + | |||
| + | (b) <math>\binom{19}{2}+\binom{18}{3}+\binom{17}{4}+\cdots \binom{11}{10}</math> | ||
| + | |||
| + | (c) <math>\binom{n-1}{2}+\binom{n-2}{3}+\binom{n-3}{4}+\cdots</math> | ||
== See also == | == See also == | ||
| − | {{ | + | {{UNCO Math Contest box|year=2009|n=II|num-b=9|num-a=11}} |
[[Category:Intermediate Algebra Problems]] | [[Category:Intermediate Algebra Problems]] | ||
Latest revision as of 00:59, 13 January 2019
Problem
Let 
. Determine the number of subsets 
of 
such that contains at least two
elements and such that no two elements of differ by 
when
(a) 
(b) 
(c) generalize for any 
.
Solution
(a) 
(b) 
(c) 
See also
| 2009 UNCO Math Contest II (Problems • Answer Key • Resources) | ||
| Preceded by Problem 9 |
Followed by Problem 11 | |
| 1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 | ||
| All UNCO Math Contest Problems and Solutions | ||
