Question 1142987
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<pre>
Let d be the distance to the school (in kilometers).


Going at the speed of  2.5 km/h, the student spends  {{{d/2.5}}}  hours.


Going at the speed  of  3 km/h, the student spends  {{{d/3}}}  hours.


The difference is 6 + 10 minutes = 16 minutes = {{{16/60}}} of an hour = {{{4/15}}}  of an hour.



It gives you the "time" equation


    {{{d/2.5}}} - {{{d/3}}} = {{{4/15}}}.


At this point, the setup is just completed.


To find "d", multiply both sides of the equation (1)  by 30.  You will get


    12d - 10d = 8,

    2d        = 8

     d        = 8/2 = 4 kilometers.


<U>ANSWER</U>.  The distance to the school is 4 kilometers.


<U>CHECK</U>.   {{{4/2.5}}} = 1.6 hours = 1 hour 36 minutes;    

         {{{4/3}}} = {{{1}}}{{{1/3}}} hours = 1 hour and 20 minutes.

         The difference is 16 minutes -- ! Correct !
</pre>

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


It is simple, &nbsp;logical, &nbsp;straightforward and economic. &nbsp;Going in this way, &nbsp;you will not make a mistake - the logic of the method 
prevents you of making mistakes.


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

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/word/travel/Had-a-car-move-faster-it-would-arrive-quicker.lesson>Had a car move faster it would arrive sooner</A>

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/word/travel/How-far-do-you-live-from-school.lesson>How far do you live from school?</A> &nbsp;&nbsp;&nbsp;(*)

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/word/travel/Earthquake-waves.lesson>Earthquake waves</A> 

&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.



For the TWIN problem, &nbsp;see the lesson &nbsp;(*) &nbsp;in the list.