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Part of 1996 China Team Selection Test
Problems(2)
each country has 9 representatives
Source: China TST 1996, problem 4
5/17/2005
3 countries participate in a competition where each country has 9 representatives. The rules are as follows: every round of competition is between 1 competitor each from 2 countries. The winner plays in the next round, while the loser is knocked out. The remaining country will then send a representative to take on the winner of the previous round. The competition begins with and sending a competitor each. If all competitors from one country have been knocked out, the competition continues between the remaining 2 countries until another country is knocked out. The remaining team is the champion.
I. At least how many games does the champion team win?
II. If the champion team won 11 matches, at least how many matches were played?
combinatorics unsolvedcombinatorics
China TST 1996 diameter circle cut
Source: China TST 1996, problem 1
5/17/2005
Let side of be the diameter of a semicircle which cuts and at and respectively. and are the feet of the perpendiculars from and to respectively. and intersect at . Prove that .
geometrytrapezoidChina