# Story problems for Algebra II/Trig review test

1. Aug 11, 2010

### roquel

1. The problem statement, all variables and given/known data
at noon a train leaves B heading East at 90 mi/h to C which is 450 miles away
at 12:15 pm a train leaves C heading West to B at 100 mi/h. When will they pass each other?

2. Relevant equations t=0 when train leaves B and train leaving C is ) at t=15min

3. The attempt at a solution Graph hours on the x axis and miles on the y axis, but how do you graph the train leaving C? I don't see how the lines intersect. Where do I go to get basic information on these types of problems?

2. Aug 12, 2010

### hgfalling

You don't need to graph anything.

Let t be the number of hours since noon that have elapsed.
Can you write down an expression in terms of t for how far apart the trains are?
(hint: they start 450 miles apart and one train leaves earlier)

Once you have done that, they will pass each other at a time t that makes your expression equal zero (because then they will be zero miles apart!)