A 38-year-old with degrees in psychology, education and computer science needed only 11.8 seconds to calculate the 13th root of a 100-digit number in his head, setting a new record, organizers said.
Onlookers with electronic calculators needed more time to solve the problem that Gert Mittring figured on his own, with two umpires checking the time, at a math museum in the small German town of Giessen near Frankfurt in western Germany.
