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=s120,
{(s120)+(s90)} =v1•6,
v2•6=120+90.
=> v2=(120+90)/6=210/6=35 mph

t=120/v1 (1)
2s210=6•v1 (2)
35•t=s120 (3)
===
Substitute (1) in (2)
35•120/v1=s120 (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 ...
 Math  Two trains leave the same station at the same time, but are headed in ...
 algebra  two trains leave at the same time from two different stations 284 ...
 Maths  Two trains, Aand B , leave a train station at the same time but in ...
 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 boys,John and Jackson are running at different speeds of 30 km/hr and...
 physics  Two vectors have magnitudes 3.0 and 4.0. How are the directions of the...
More Related Questions