SOLUTION: trains A and B are traveling in the same direction on the parallel tracks. train A is traveling 80 miles per hour and train B is traveling at 90 miles per hour. Train A passed a s

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Question 163033: trains A and B are traveling in the same direction on the parallel tracks. train A is traveling 80 miles per hour and train B is traveling at 90 miles per hour. Train A passed a station at 1:20am if train B passes the same station at 1:32am At what time till train B catch up with train A?
Found 2 solutions by ankor@dixie-net.com, jojo14344:
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
trains A and B are traveling in the same direction on the parallel tracks. train A is traveling 80 miles per hour and train B is traveling at 90 miles per hour. Train A passed a station at 1:20am if train B passes the same station at 1:32am At what time will train B catch up with train A?
:
An easy to do this is use the relative speed between the trains which is:
90 - 80 = 10 mph
:
At 1:20 Train B is 12 min behind A
:
12%2F60*90 = 18 mi
:
At the relative speed of 10 mph, how long will it take to cover 18 mi?
18%2F10 = 1.8 hrs which is 1 hr 48 min
:
1:20 + 1:48 = 3:02 train b catches train a

Answer by jojo14344(1513) About Me  (Show Source):
You can put this solution on YOUR website!

When Train B passed the station At 1:32am, how far is Train A since it passed the station earlier at 1:20am? Let's see the distance of Train A:
Remember: Speed=distance%2Ftime-----> working eqn
We get via working eqn,
d%5BA%5D=S%5BA%5Dt%5BA%5D
What will be t%5BA%5D?
The difference when Train B and Train A passed the station:
Difference: 12mins---system%281%3A32%2C-1%3A20%29
So,
highlight%28d%5BA%5D=16miles%29, Take note of this. This is how far Train A was when Train B passed the station by 1:32am.
.
In finding for time, remember too d%5BA%5D=d%5BB%5D since they're travelling on both directions. Via working eqn,
d%5BA%5D=d%5BB%5D
S%5BA%5D%28t%29%2Bhighlight%2816%29=S%5BB%5D%28t%29 . Take note highlighted, we need to add 16miles because Train A was already ahead that much, being ahead 12 minutes remember?
Continuing,
80t%2B16=90t
16=90t-80t
16=10t ---> cross%2816%291.6%2Fcross%2810%29=cross%2810%29t%2Fcross%2810%29
t=%281.6cross%28hrs%29%29%2860min%2F1cross%28hr%29%29=96mins = 1hr &36mins
Therefore,
highlight%283%3A08am%29 ---system%281%3A32am%2C%2B1%3A36%29
This is the time when Train A & Train B will be on the same distance.
In doubt? Go back working eqn,
d%5BA%5D=80%2A1.6%2B16miles=144miles
d%5BB%5D=90%2A1.6=144miles
d%5BA%5D=d%5BB%5D right?
Thank you,
Jojo