Wednesday, February 18, 2009

Rate-Time-Distance Word Problems Part 2

Now for the second part of the rate-time-distance problems. This example refers to opposite direction travel.

Let’s look at the following example:

Train 1 leaves the train station travelling south at a rate of speed that is 10 mph more than train 2 which is travelling north. After 3 hours, they are 450 miles apart. Find the rate of train 2.

We are going to use another table to organize the rate, time and distance information.

Train

Rate

Time

Distance

1

r +10

3

3 (r + 10)

2

r

3

3r



Since the trains are moving in opposite directions, we are going to add their distances together to get 450 miles.

3 (r + 10) + 3r = 450
3r + 30 + 3r = 450
6r + 30 = 450
6r = 420
r = 70

Therefore the rate of train 2 is 70 mph.

3 comments:

Anonymous said...

Please do some Gauss Jordan problems. I need help with that!

D Johnson said...

at first i didnt kno how to do it but now i think i got it its pretty simple once u get it!

Anonymous said...

once i got to looking at these problems i got to get used to them and understood them.
-H Abbott