Question 1138286
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<pre>
Let d be the distance from the epicenter of the earthquake to the station (in kilometers).


For P-wave, the traveling time is  {{{d/5}}} seconds.


For S-wave, the traveling time is  {{{d/3}}} seconds.


The difference is


    {{{d/3}}} - {{{d/5}}} = 40  seconds.


It is your "time" equation.


To solve it, multiply all terms by 15 = 3*5.  You will get


    5d - 3d = 15*40

    2d = 600

    d = 300 kilometers.


<U>ANSWER</U>.  The distance from the epicenter of the earthquake to the station is 300 kilometers.
</pre>

Solved.


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From my post, lean on how to write, to solve and to use a "time" equation.


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

&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/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> 

in this site.



Also, &nbsp;you have this free of charge online textbook in ALGEBRA-I in this site

&nbsp;&nbsp;&nbsp;&nbsp;<A HREF=https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson>ALGEBRA-I - YOUR ONLINE TEXTBOOK</A>.


The referred lessons are the part of this textbook under the section "<U>Word problems</U>", &nbsp;the topic "<U>Travel and Distance problems</U>".



Save the link to this online textbook together with its description


Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson


to your archive and use it when it is needed.