Distance Formula Problem

by Jay
(Los Angeles)

It takes a passenger train 2 hrs less time than a freight train to make the trip from Central City to Clear Creek. The passenger train averages 96 km/h while the freight train averages 64 km/h. How far is it from Central City to Clear Creek?

Comments for
Distance Formula Problem

Average Rating starstarstarstarstar

Click here to add your own comments

Mar 01, 2010
Rating
starstarstarstarstar
Distance Formula Problem
by: Karin

Dear Jay,
You must use the distance formula to solve this problem. We will use the distance formula for the freight train and the passenger train.

freight: d= rt
passenger: d = rt

We know that the passenger train takes 2 less hours than the freight train. We don't know how long the freight train takes, so we are going to let our variable x = the number of hours for the freight train.

So we know:
freight: time = x, rate = 64km/hour
passenger: time = x -2 rate = 96 km/hour

We also know that the two trains are traveling the same distance, so we are going to set these two equations equal to each other.
freight distance = passenger distance
rt = rt
64x = 96(x-2)
64x = 96x - 192 Distribute
64x - 96x = 96x -96x -192 Subtract 96x from both sides.
-32x = -192
-32x/-32 = -192/-32
x = 6

Since x = 6 we know that the freight train takes 6 hours and the passenger train takes 4 hours.

So, let's figure out the distance - it should be the same for both trains.

freight: d= rt d = 64(6) d = 384 km
passenger: d = rt d = 96(4) d = 384 km

Therefore, the distance is 384 km.

Hope this helps!

All the best,
Karin

Click here to add your own comments

Join in and write your own page! It's easy to do. How?
Simply click here to return to Students





[ ?] Subscribe To This Site

XML RSS
Add to Google
Add to My Yahoo!
Add to My MSN
Add to Newsgator
Subscribe with Bloglines


Enjoy This Site?
Then why not use the button below, to add us to your favorite bookmarking service?

Copyright© Algebra-class.com 2009.