Luke Robitaille, left, and Andrew Cai, right.Raytheon Company
Thirteen-year-old Luke Robitaille was named the 2017 Raytheon Mathcounts National Champion, beating a field of 224 to take home the top prize.
The competition aired live on ESPN3 on Monday, May 15, at 10 a.m. ET.
Robitaille, a seventh grade home school student from Euless, Texas, answered the following question correctly to win:
"In a barn, 100 chicks sit peacefully in a circle. Suddenly, each chick randomly pecks the chick immediately to its left or right. What is the expected number of un-pecked chicks?"
He hit his buzzer in .9 seconds with the right answer.
"We've never had a student win the championship on a question that quickly before," Lou DiGioia, executive director of Mathcounts, told Business Insider. "The speed with which he can do mental calculations is extraordinary," he continued.
DiGioia, walked Business Insider through the way to come to the correct answer of the winning question. He explained:
"For any one chick, there are four possible outcomes: being pecked only by the chick to its left, being pecked only by the chick to its right, being pecked by both the chicks, or being pecked by neither of the chicks.
"Each of the four outcomes is equally probable, so there is a one in four chance of any chick being un-pecked. Since there are 100 chicks in the circle we can expected, ¼ * 100 = 25 un-pecked."
The correct answer of the question is 25.
Robitaille won $24,500 in the 2017 competition: $20,000 for winning the Countdown Round, $2,000 for being member of winning team, and $2,500 for winning a written competition. Last year, he won $9,500 as runner-up in the competition.
While 224 competitors made it to the national competition, more than 100,000 students participated in qualifying rounds for local and state competitions, a press release from Raytheon stated. This marks the 34th year of the Mathcounts competition.
