SOLUTION: Lisa left camp on her bike at noon and rode at an avg rate of 10mph. Morton left in his van at 1;30pm traveling 35mph. how long till morton catches up with lisa?

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Question 512113: Lisa left camp on her bike at noon and rode at an avg rate of 10mph. Morton left in his van at 1;30pm traveling 35mph. how long till morton catches up with lisa?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
First find Lisa's head start in miles
+10%2A1.5+=+15+ mi ( note that 1.5 is time from noon to 1:30 )
Let +d+ = distance Morton has to go to catch Lisa
Let +t+ = time from when Morton
leaves to when he catches Lisa
-----------------
given:
Morton:
(1) +d+=+35t+
Lisa:
(2) +d+-+15+=+10t+
----------------
substitute (1) in (2)
(2) +35t+-+15+=+10t%0D%0A%282%29+%7B%7B%7B+25t+=+15+
(2) +t+=+.6+ hr
+.6%2A60+=+36+ min
Morton catches Lisa in 36 min, or at 2:06 PM
check:
(1) +d+=+35t+
(1) +d+=+35%2A.6+
(1) +d+=+21+ mi
and
(2) +d+-+15+=+10t+
(2) +d+-+15+=+10%2A.6+
(2) +d+=+15+%2B+6+
(2) +d+=+21+ mi
OK