Answer: 15 seconds
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Work shown:
distance = rate*time
300 = 20*t
300/20 = 20t/20 .... divide both sides by 20
15 = t
t = 15
It will take him 15 seconds to travel 300 meters.
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Side notes:
- 300 meters = 984.25 feet = 0.19 miles approximately
- 20 m/s = 44.74 mph approximately