A six-man U.S. team won the International Mathematical Olympiad for the first time since 1994, edging out China. There will not be a parade.
Over three decades, China has won the math Olympiad 19 times, notes the Los Angeles Times.
Team members must solve six problems that require algebra, geometry, number theory and combinators in 4 1/2-hour sessions over two days.
Here’s an example from last year:
Let n ? 2 be an integer. Consider an n x n chessboard consisting of n2 unit squares. A configuration of n rooks on this board is peaceful if every row and every column contains exactly one rook. Find the greatest positive integer k such that, for each peaceful configuration of n rooks, there is a k x k square which does not contain a rook on any of its k2 unit squares.
Although there were no girls on the U.S. squad, two girls ranked among the top 12 competitors in the United States, said Po-Shen Loh, the Carnegie Mellon professor who coached the team. (Nine of the 12 U.S. finalists were Asian-American.)
Ukraine, with three girls on the team, was the only gender-balanced squad in the Olympiad.
Few girls compete in the international competition, notes the FiveThirtyEight blog. In recent years, the average number of girls per team has risen from 0.2 in the 1970s to 0.5 in the 2010s (so far).