Answer:
20 meters.
Explanation:
Well, Andy had finished the 100 meter race before everyone else. This obviously means that he/she had already ran 100 meters. Blaise was 10 meters behind Andy meaning he was at 90 meters. Then Susie was 10 meters behind Susie, meaning Susie was at 80 meters while Andy was at 100. Finally 100-80=20
or
10+10=20