Posted by **Stephanie** on Wednesday, December 5, 2012 at 5:08pm.

At the same time but different speeds, two trains X and Y left from different stations, A and B, and moved facing each other (to opposite directions). They first met at the point that was 120 miles from station A. When X and Y reached the destinations (B and A respectively), they moved back without stop. 6 hours later after they first met, two trains met again. This time, the meeting point was 90 miles from station A. Suppose each of them was moving all the time at a constant rate, what were the speeds of train X and Y (X and Y had different rate)?

- Math 310 Math for Teachers -
**Elena**, Wednesday, December 5, 2012 at 5:55pm
v(X)=v1

v(Y) = v2

s is the distance between A and B

t is the time before the 1st meeting

v1•t=120,

v2•t=s-120,

{(s-120)+(s-90)} =v1•6,

v2•6=120+90.

=> v2=(120+90)/6=210/6=35 mph

-----

t=120/v1 (1)

2s-210=6•v1 (2)

35•t=s-120 (3)

===

Substitute (1) in (2)

35•120/v1=s-120 (4)

From(3)

s= 3•v1+105 (5)

Plug (5) in (4)

v1² - 5•v1- 35•40=0

v1= 40 mph

## Answer this Question

## Related Questions

- math - Two trains depart at the same time from the same station and travel in ...
- math - Two trains depart at the same time from the same station and travel in ...
- math - Supppose two trains leave Holbrook, Arizona, at the same time, traveling ...
- algebra - two trains leave at the same time from two different stations 284 ...
- Physics - Two trains travel on the same railway in opposite direction. The ...
- math - 2 trains going opposite directions leave at the same time. Train b is ...
- math - two trains leave at the same time from stations 284 miles apart, ...
- math - The distance between Delhi and Meerut is 75km . Two trains at a speed of ...
- math - A northbound train and a southbound train meet each other on parallel ...
- Math - An eastbound train and a westbound train meet each other on parallel ...