.
If the order of these winners in pairs is important, then the number of ways is 3*2 = 6
AB, AC, BC, BA, CA, CB.
If the order of these winners in pairs is not important, then the number of ways is 3
AB, AC, BC.
Since the wording in your post does not allow to distinct between these two
possible configurations, it is not possible to give a unique answer.
The correct way to ask the question is THIS:
Racers A, B and C have the greatest chance of winning the race.
How many different ways can the first two positions be placed
(a) if the order in pairs is important ?
(b) if the order in pairs is not important ?
Then the questions are clear, and the answers are clear, as well.
