SOLUTION: Simon drove from Town A to Town B at an average speed of 55kph. His journey back to town A using the same route took 3 hours longer because he averaged only 40 kph. How long did it

Algebra ->  Customizable Word Problem Solvers  -> Age -> SOLUTION: Simon drove from Town A to Town B at an average speed of 55kph. His journey back to town A using the same route took 3 hours longer because he averaged only 40 kph. How long did it      Log On

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Question 1135013: Simon drove from Town A to Town B at an average speed of 55kph. His journey back to town A using the same route took 3 hours longer because he averaged only 40 kph. How long did it take him to drive from town A to Town B?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +d+ = distance between towns in km
Let +t+ = time to go from A to B in hrs
+t+%2B+3+ = time to go from B to A in hrs
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Going from A to B
(1) +d+=+55t+
Going from B to A:
(2) +d+=+40%2A%28+t+%2B+3+%29+
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Plug (1) into (2)
(2) +55t+=+40t+%2B+120+
(2) +15t+=+120+
(2) +t+=+8+
It took 8 hrs to go from A to B
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check:
(1) +d+=+55%2A8+
(1) +d+=+440+ km
and
(2) +d+=+40%2A11+
(2) +d+=+440+ km
OK