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Running at an average rate of 10 m/s, a sprinter ran to the end of a track and then jogged back to the starting point at an average of 5 m/s. The sprinter took 60 s to run to the end of the track and jog back. Find the length of the track.

d=300md is equal to 300 m

d=200md is equal to 200 m

d=600md is equal to 600 m

d=150md is equal to 150 m

User Petro Semeniuk
by
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1 Answer

10 votes
10 votes

9514 1404 393

Answer:

200 m

Explanation:

Let d represent the length of the track in meters. The relation of interest is ...

time = distance/speed

Then the total time to run and walk back is ...

60 = d/10 + d/5

600 = d + 2d

200 = d . . . . . . . divide by 3

The length of the track is 200 meters.

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200 m in 20 seconds is a world-record time for a woman; a very good time for a man.

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