SOLUTION: train travelling @ 40kph leaves 10 mins before train travelling @ 60kph.when will they meet??

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: train travelling @ 40kph leaves 10 mins before train travelling @ 60kph.when will they meet??      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 397193: train travelling @ 40kph leaves 10 mins before train travelling @ 60kph.when will they meet??
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
How far does the 1st train get in 10 min?
d%5B1%5D+=+40%2A%281%2F6%29 (10 min is 1/6 of an hour)
d%5B1%5D+=+20%2F3 km
Now if the 2nd train has to travel d km to
meet the 1st train, then the 1st train has to
travel d+-+20%2F3 km
They will both travel for the same time period
1st train:
(1) d+-+20%2F3+=+40t
2nd train:
(2) d+=+60t
Substitute (2) in (1)
60t+-+20%2F3+=+40t
180t+-+20+=+120t
60t+=+20
t+=+1%2F3 hr
They will meet 20 min after the 2nd train leaves
check answer:
(2) d+=+60t
d+=+60%2A%281%2F3%29
d+=+20 km
and
(1) d+-+20%2F3+=+40t
20+-+20%2F3+=+40%2A%281%2F3%29
60+-+20+=+120%2A%281%2F3%29
40+=+40
OK