Question 1087384
.
You forgot to mention in the condition that both objects A and B started from the same point.


<pre>
Then the time under the question is

t = {{{(2*60)/(3.0-2.0)}}} = {{{120/1}}} = 120 seconds = 2 minutes.


The numerator 2*60 is the distance in meters from the starting point to A at the moment when the object B starts his move 
    (2 minutes = 120 seconds after A started its move).


So the numerator is the "ahead distance" between A and B when B started catching A.


The denominator (3.0 - 2.0) = 1 m/s is the relative speed of the body B to body A.
</pre>


<U>Solved</U>.



On catching 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.



Also, 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 lesson is the part of this textbook under the section "<U>Word problems</U>", the topic "<U>Travel and Distance problems</U>".