OMK 2010
Source: Malaysia National Olympiad 2010 Bongsu Category Problem 9
June 4, 2011
algebra
Problem Statement
A number of runners competed in a race. When Ammar finished, there were half as many runners who had finished before him compared to the number who finished behind him. Julia was the 10th runner to finish behind Ammar. There were twice as many runners who had finished before Julia compared to the number who finished behind her. How many runners were there in the race?