SOLUTION: 4.) Train A and B start at the same time, traveling toward each other from two stations that are 600 miles apart. The trains are still 120 miles apart after 4 hours. Given that the

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: 4.) Train A and B start at the same time, traveling toward each other from two stations that are 600 miles apart. The trains are still 120 miles apart after 4 hours. Given that the      Log On


   



Question 890101: 4.) Train A and B start at the same time, traveling toward each other from two stations that are 600 miles apart. The trains are still 120 miles apart after 4 hours. Given that the average rate of speed of train B is 10 miles per hour faster than the average rate of speed of train A, what is the average rate of speed, in miles per hour, of train A?
Answer by josgarithmetic(39614) About Me  (Show Source):
You can put this solution on YOUR website!
_____________speed_________time________distance
Train A______r_____________4___________r*4
Train B______r+10__________4___________(r+10)*4
TOTAL__________________________________600-120=highlight_green%28r%2A4%2B%28r%2B10%29%2A4=480%29

The combined distances traveled after 4 hours is 480 miles, ignoring the length of the trains.
Solve for r.

4r%2B4r%2B40=480
8r%2B40=480
8r=440
r=4%2A11%2A10%2F8
r=4%2A11%2A2%2A5%2F%284%2A2%29
highlight%28r=55%29