One hundred riders from several countries participated in a bicycle race. Only eighty riders, including Tom and Ravi, finished the race. Tom finished 5 " and Ravi was the winner. All the riders' countries of origin and finishing times were recorded on the race register. No two riders who finished had the same time and those who did not finish were recorded as DNF. Based on this information, determine if each set is well-defined. Is the set well-defined? Set Yes No The set of riders with the best looking bicycles O O The set of riders who finished 10 minutes or more after the winner O O The set of countries of origin of the riders that didn't finish O O The set of the three least tired riders at the end O O The set of riders who finished the race O O X 5