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| Question 1017257:  Two planes, which are 2320 miles apart, fly toward each other. Their speeds differ by 80 mph.  If they pass each other in 4 hours, what is the speed of each?
 Answer by ikleyn(52879)
      (Show Source): 
You can put this solution on YOUR website! . Two planes, which are 2320 miles apart, fly toward each other. Their speeds differ by 80 mph.
 If they pass each other in 4 hours, what is the speed of each?
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Let x be the speed of the slower plane, in mph.
The the speed of the other plane is x +80 mph.
The distance between two planes decreases at the rate x + (x+80) = 2x + 80 mph.
You have this equation
 = 4.
Solve it. For it, multiply both sides by (2x + 80). You will get
2320 = 4*(2x + 80),   or
2320 = 8x + 320,   or
8x = 2000.
Hence, x =  = 250 mph. It is the speed of the slower airplane.
The speed of the faster is 250 + 80 = 330 mph. 
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