388 views
0 votes
0 votes
Suppose that $21$ girls and $21$ boys enter a mathematics competition. Furthermore, suppose that each entrant solves at most six questions, and for every boy-girl pair, there is at least one question that they both solved. Show that there is a question that was solved by at least three girls and at least three boys.

Please log in or register to answer this question.

Related questions

0 votes
0 votes
0 answers
1
admin asked Apr 29, 2020
456 views
There are $51$ houses on a street. Each house has an address between $1000\: \text{and}\: 1099,$ inclusive. Show that at least two houses have addresses that are consecut...
0 votes
0 votes
0 answers
3