Question 1186142
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The remaining trip is  20 - 5 = 15 miles long.

Mike spends  {{{5/20}}} = {{{1/4}}}  of an hour = 15 minutes for the first part of the trip;

hence, he spends 30 - 15 = 15 minutes for the remaining part.



Thus Mike moves remaining part of 15 miles in 15 minutes;

hence, his speed is 1 mile per minute, or 60 miles per hour.    <U>ANSWER</U>
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Solved and thoroughly explained.