Question 1138509
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Kyle spent  {{{4/10}}}  of an hour on the level ground part of the length 4 = {{{12/3}}} miles.


Then he spent  {{{4/6}}} = {{{2/3}}}  of an hour on the uphill part of the same length 4 = {{{12/3}}} miles.


Finally, he spent  {{{4/15}}} of an hour on the downhill part of the same length 4 = {{{12/3}}} miles.


In all, he spent  {{{4/10 + 2/3 + 4/15}}} = {{{12/30 + 20/30 + 8/30}}} = {{{40/30}}} = {{{4/3}}} hours for the entire 12-miles trip.


<U>ANSWER</U>.  His trip took  {{{4/3}}} hours = {{{1}}}{{{1/3}}} hours = 1 hour and 20 minutes.
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