time Speed problem.

[koukla]

hereis my problem:
A train leaves Las Vegas heading Wesst to las Angeles.
At the same time, a bus 272 miles away ,in las Angeles heads East toward las Vegas.
If the train travels 31 mph faster than the bus, and they pass each other in 2 hours, what is the ave speed of the train, and of the Bus?
HELP!!
I don't know how to set up the equation.

 

[JeffM]

hereis my problem:
A train leaves Las Vegas heading Wesst to las Angeles.
At the same time, a bus 272 miles away ,in las Angeles heads East toward las Vegas.
If the train travels 31 mph faster than the bus, and they pass each other in 2 hours, what is the ave speed of the train, and of the Bus?
HELP!!
I don't know how to set up the equation.

The way to start on ANY word problem that gives you ANY trouble is to WRITE down symbols for each potential variable and then to WRITE down the known or given relationships among them USING the symbols you have chosen..

With time/distance/speed problens the relationship is always the same, namely average speed * time = distance.

I'll start assigning symbols
a = average speed of train
b = distance travelled by train
c = time = 2 hours = 120 minutes

You continue

d = ?????