Question 1092774
.
<pre>
D1 = 100*t  is the "distance" equation for the first train.

D2 =  90*t  is the "distance" equation for the second train.


D1 + D2 = 456   (given)   =====>


100t + 90t = 456  ====>  (100+90)*t = 456  ====>  190t = 456  ====>  t = {{{456/190}}} hours = 2.4 hours = 2 hours and 24 minutes.
</pre>

Solved.



-----------
On Travel and distance problems, read the lessons

- <A HREF=http://www.algebra.com/algebra/homework/word/travel/Travel-and-Distance-problems.lesson>Travel and Distance problems</A>  

- <A HREF=https://www.algebra.com/algebra/homework/word/travel/Travel-and-Distance-problems-for-two-bodies-moving-toward-each-other.lesson>Travel and Distance problems for two bodies moving in opposite directions</A> 

- <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.