SOLUTION: 2 airplanes start at the same place and fly in opposite directions. The average rate of one plane is 18 miles per hour faster than the other one. Find the rate of each plane if the

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Question 1110174: 2 airplanes start at the same place and fly in opposite directions. The average rate of one plane is 18 miles per hour faster than the other one. Find the rate of each plane if they are 1179 miles apart after 1 1/2 hours.
Found 2 solutions by ikleyn, josmiceli:
Answer by ikleyn(52756)   (Show Source): You can put this solution on YOUR website!
.
Distance by the 1-st airplane + Distance by the 2-nd airplane = 1179 miles.


                             +                  = 1179     ( =  hours =  hours)



Multiply both sides by 2:


3r + 3*(r+18) = 1179*2

3r + 3r + 54 = 2358

6r = 2358 - 54 = 2304  ====>  r =  = 384 miles per hour.


Answer.  The slower airplane speed is 384 mph.

         The faster is 384 + 18 = 402 mph.

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On introductory lessons on Travel and Distance problems see the lessons
    - Travel and Distance problems
    - Travel and Distance problems for two bodies moving in opposite directions
    - Travel and Distance problems for two bodies moving in the same direction (catching up)
in this site.


Answer by josmiceli(19441)   (Show Source): You can put this solution on YOUR website!
= the speed of the slower plane
= the speed of the faster plane
------------------------------------------
You can think of this as one of the planes
flying at the sum of their speeds, and the
other plane standing still
------------------------------------------





and


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The rates of the planes are 384 mi/hr and 402 mi/hr
----------------------------------------------------
check the answer:


and


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OK
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