<h2>
Marathon distance is 42.19 km</h2>
Explanation:
The Olympic record for the marathon = 2.00 h, 9.00 min, 21.0 s
The Olympic record for the marathon = 2 x 60 x 60 + 9 x 60 + 21 = 7761 s
Average speed of a runner achieving this record = 5.436 m/s
Marathon distance = Time for running x Average speed
Marathon distance = 7761 x 5.436
Marathon distance = 42188.8 m
Marathon distance = 42.19 km
Marathon distance is 42.19 km
