SOLUTION: Chantel leaves her home in Milwaukee on trip to St Louis at 8:00am. She is stuck behind a WI state trooper and averages a perfect 65 mph. At 8:15am, Chantel's mom notices that she

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Chantel leaves her home in Milwaukee on trip to St Louis at 8:00am. She is stuck behind a WI state trooper and averages a perfect 65 mph. At 8:15am, Chantel's mom notices that she      Log On


   



Question 840750: Chantel leaves her home in Milwaukee on trip to St Louis at 8:00am. She is stuck behind a WI state trooper and averages a perfect 65 mph. At 8:15am, Chantel's mom notices that she has forgotten her phone, so she chases after her at 72 mph. How long will it take Chantel's mom to catch Chantel?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
How much of a head start does Chantel get from
8:00 to 8:15 ?
+d%5B1%5D+=+65%2A%281%2F4+%29+ ( 15 min is 1/4 hr )
+d%5B1%5D+=+16.25+
Start a stopwatch when her mom leaves at 8:15
Let +d+ = the distance in miles that her mom
travels until she catches her daughter
Let +t+ = the time in hrs on the stopwatch when
her mom catches up with her
-------------------------------
Chantel's equation:
(1) +d+-+16.25+=+65t+
Mom's equation:
(2) +d+=+72t+
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By substitution:
(1) +72t+-+16.25+=+65t+
(1) +7t+=+16.25+
(1) +t+=+2.321+
+.321%2A60+=+19.286+
+.286%2A60+=+17+
It will take her mom 2 hrs 19 min 17 sec
to catch Chantel
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check:
(1) +d+-+16.25+=+65%2A2.321+
(1) +d+=+150.865+%2B+16.25+
(1) +d+=+167.115+
and
(2) +d+=+72%2A2.321+
(2) +d+=+167.112+
close enough