Vlad is back

by shiningsunnyday, Nov 27, 2016, 2:22 PM

Combo 3 homework (Medium) wrote:
$200$ students participated in a mathematical contest. They had $6$ problems to solve. It is known that each problem was correctly solved by at least $120$ participants. Prove there must be $2$ participants such that every problem was solved by at least one of these $2$ participants.
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oooooorrrr you could do something probabilistically! pick two random students. what’s the probability that the first problem wasn’t solved by both? the second problem? etc

yo no time to dawdle we need to go back to working on isef
This post has been edited 1 time. Last edited by shiningsunnyday, Nov 27, 2016, 2:29 PM

by cjquines0, Nov 27, 2016, 2:29 PM

To share with readers my favorite problem I came across today :) (Shout for contrib.)

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