Question 1085194
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<pre>
Let t = "How long until the mother catches up".

Then  t = {{{((10*(12/60)))/(((22-10)/60))}}}.


The numerator {{{(10*(12/60))}}} is the distance between them when mother started move.


The denominator is their relative speed, in miles per minute.


So, t = {{{(10*12)/12}}} = 10 minutes.
</pre>

On catching up problems see the lesson

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/word/travel/Typical-catching-up-Travel-and-Distance-problems.lesson>Travel and Distance problems for two bodies moving in the same direction (catching up)</A>

in this site.