Word Problem

[debbie29]

It takes a freight train 2 hours longer to travel 300 miles than it takes
an express train to travel 280 miles. The rate of the express train is 20
miles per hour greater than the rate of the freight train. Find the times
and rates of both trains.

This is what I have:

Train A (Freight)= 300 / r / t+2

Train B (Express)= 280/r+20/ t

t= 300/r+2 ; t=280/ r+20
Thus 300/r =280/r+20

r (r+20)* 300/r= r (r+20) 280/r+20

300 (r+20)= 280r
300(r+20)= 280r- 6,000 (300 * 20)
6000= 20r
300=r

If r= 300, then the speed of train A is 300+320= 320mph.

******That is as much as I have, I scrapped the rest because I keep getting wrong answers.Any tips on how to fix it would be appreciated! The above formula is what the textbook used.

 

[stapel]

Thank you for showing your work!

I'm going to guess that your fraction-ish looking things are actually entries in some sort of table. It might help if you wrote things out line-by-line, and defined terms as you went.

. . . . .freight:
. . . . .distance: 300
. . . . .rate: r
. . . . .time: 300/r

. . . . .express:
. . . . .distance: 280
. . . . .rate: r + 20
. . . . .time: 280/(r + 20)

. . . . .(freight's time) was (express' time) plus (two hours)

Translate the sentence above into an equation, and solve for the rate "r" of the freight.

(You've got the two rates as being "r + 2" and "r + 20". But what then does "r" stand for? The rate of some third train?)

Eliz.

 

[debbie29]

great. I'll try that. Thank you very much!

Deb