Help please and Thank you

20 minutes is 1/3 of an hour, so an hour can be split into 3 20 minute sections.
They run 4 miles each 20 minute section equals 4 x 3 = 12 miles per hour.
Answer:
[tex]12\:mph[/tex]
Step-by-step explanation:
Multiply the proportion [both denominator and numerator] by 3, since you have to multiply 20 by 3 to get one hour. Then, whatever is done to the bottom is also done to the top, so 3 by 4 is 12, therefore you have 12 mph.
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