Question 1208414
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To be honest, I do not see any setup here, since this writing does not contain a complete equation.


The way for reasoning and for making setup is as follows.


<pre>
    Let n be the number of revolutions (same as rotations).

    One rotation provides {{{pi*d}}} = {{{4pi}} feet move forward.

     "n" rotations provide {{{4*n*pi}}} feet move forward.

    The setup equation is

        {{{4*n*pi}}} = 20  feet.


     The solution is  n = {{{20/(4pi)}}} = {{{20/(4*3.14)}}} = 1.595727... rotations.
</pre>

Thank you for asking and have a nice day !