SOLUTION: Mr. Abou leaves Edmonton traveling north at an average speed of 60 km/h. An hour later Mr. Collins leaves on the same route at 100km/h. How many hours after he left, did Mr. Collin

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Question 1046861: Mr. Abou leaves Edmonton traveling north at an average speed of 60 km/h. An hour later Mr. Collins leaves on the same route at 100km/h. How many hours after he left, did Mr. Collins overtake Mr. Abou?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
What is Mr Abou's head start in km ?
+d%5B1%5D+=+60%2A1+
+d%5B1%5D+=+60+ km
----------------------
Start a stopwatch when Mr Collins leaves
Let +t+ = the time on the stopwatch in hrs
when Mr Collins catches up with Mr Abou
Let +d+ = distance in km that Mr Collins
travels until he catches up with Mr Abou
----------------------------------------
Mr Collins equation:
(1) +d+=+100t+
Mr Abou's equation:
(2) +d+-+60+=+60t+
--------------------
Substitute (1) into (2)
(2) +100t+-+60+=+60t+
(2) +40t+=+60+
(2) +t+=+1.5+
In 1 hr 30 min, Mr Collins catches up
with Mr Abou
------------------
check:
(1) +d+=+100t+
(1) +d+=+100%2A1.5+
(1) +d+=+150+ km
and
(2) +d+-+60+=+60t+
(2) +d+-+60+=+60%2A1.5+
(2) +d+=+60+%2B+90+
(2) +d+=+150+ km
OK