Question 1156011
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<pre>

Let "d" be one-way distance.


He spent  {{{d/40}}}  hours driving "to there".


He spent  {{{d/30}}}  hours driving back.


The total time is 7 hours:

    {{{d/40}}} + {{{d/30}}} = 7  hours.


You get your basic equation. It is called the "time" equation.


To solve it, multiply both sides by 120.  You will get

    3d + 4d = 7*120

    7d      = 7*120

     d      = 120  kilometers.


<U>ANSWER</U>.  One way distance is 120 kilometers.  Total (two-ways) distance is 240 km.


<U>CHECK</U>.  {{{120/40}}} + {{{120/30}}} = 3 + 4 = 7 hours.   ! Precisely correct !
</pre>

SOLVED.


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Using &nbsp;"time" &nbsp;equation is a &nbsp;STANDARD &nbsp;method of solving such problems.

From this lesson, &nbsp;learn on how to write, &nbsp;how to use and how to solve a &nbsp;"time" &nbsp;equation.


To see many other similar solved problems, &nbsp;look into the lessons

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&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/word/travel/Time-equation-HOW-TO-write-it-and-how-to-solve-it.lesson>Time equation: HOW TO use, HOW TO write and HOW TO solve it</A> 

in this site.