SOLUTION: Andy is driving in a straight line on the freeway heading east. Morgan is driving on the same freeway heading west. At 1:00 p.m., they are exactly 60 miles apart. They pass each

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: Andy is driving in a straight line on the freeway heading east. Morgan is driving on the same freeway heading west. At 1:00 p.m., they are exactly 60 miles apart. They pass each      Log On

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Question 979108: Andy is driving in a straight line on the freeway heading east. Morgan is driving on the same freeway heading west. At 1:00 p.m., they are exactly 60 miles apart. They pass each other at 1:30 p.m. If Andy is driving at 55 miles per hour, at what speed is Morgan driving?
Please explain in detail! Thanks.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
When they are +60+ mi apart, Just imagine
that one of them, say Morgan, stops and the
other, Andy, starts heading toward Morgan at
the sum of their speeds.
--------------------------
Let Morgan's speed = +s+ mi/hr
The sum of their speeds is: +55+%2B+s+ mi/hr
They pass eachother in +1%2F2+ hr
--------------------------
Now I can say:
+60+=+%28+55+%2B+s+%29%2A%281%2F2%29+
+120+=+55+%2B+s+
+s+=+65+
Morgan is driving 65 mi/hr
--------------------------
check:
Andy's equation:
+d%5B1%5D+=+55%2A%281%2F2%29+
+d%5B1%5D+=+27.5+ mi
--------------------
Morgan's euation:
+d%5B2%5D+=+65%2A%281%2F2%29+
+d%5B2%5D+=+32.5+ mi
--------------------
+d%5B1%5D+%2B+d%5B2%5D+=+27.5+%2B+32.5+
+d%5B1%5D+%2B+d%5B2%5D+=+60+ mi
OK