A record for a marathon is 2.00h, 9.00min, 21.0 sec. If the average speed of a runner achieving this record is 5.436 m/s, what is the marathon distance?

Answers:
15,878 km
7,761 km
42.2 km
26.2 km

We're omnly two days into the new school year and I don't have all the formulas straight-please help
Thank you

2 answers

t = 2hr*3600s/hr + 9mim*60s/m + 21s = 7761s.
d = 5.436m/s *7761s = 42188.8m = 42.2km.
Thank you-Much appreciated
It makes sense now