9514 1404 393
Answer:
Adam
Step-by-step explanation:
It is pretty easy to make comparisons to 10 ft/s.
If Liz ran 10 ft/s, she would run 460 ft in 46 s. Since she runs 420 ft, she runs slower than that.
If Emily ran 10 ft/s, she would run 600 ft in 1 minute, so Emily runs faster than that.
If Adam ran 10 ft/s, he would only run 4270 ft in 427 seconds. Since he runs 5280 ft in that time, his speed is definitely greater than 10 ft/s.
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At this point, we know that Adam and Emily run faster than Liz and Stephanie. So we need to compare Adam and Emily's rates.
Adam's time for 1 mile is about 7 minutes. If Emily ran for 7 minutes, her distance would be less than 7×700 ft = 4900 ft, substantially less than 1 mile (5280 ft).
Adam runs the fastest.
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<em>Comment on straightforward solution</em>
Each rate can be computed by dividing distance by time:
Liz: (420 ft)/(46 s) = 9.13 ft/s
Adam: (5280 ft)/(427 s) = 12.37 ft/s
Emily: (667 ft)/60 s) = 11.12 ft/s
Adam's is the highest, well above Stephanie's 10 ft/s.
These calculations require a calculator. The solution above was done without a calculator.
