Difference between revisions of "Complementary counting"

(Added another problem which contains this technique)
Line 9: Line 9:
  
 
=== Somewhat Harder ===
 
=== Somewhat Harder ===
* [[2004_AIME_I_Problems/Problem_15]]
+
* [[2004 AIME I Problems/Problem 15]]
  
 
=== See also ===
 
=== See also ===

Revision as of 21:54, 28 February 2017

Complementary counting is counting the complement of the set we want to count, and subtracting that from the total number of possibilities, or the universal set for that particular problem. A big hint that complementary counting may lead to a quick solution is the phrase "at least".


Examples

Introductory

Somewhat Harder

See also