<PRE><B>Question 86323</B>
A Piper Cub airplane has an average air speed that is 10mph faster than a Cessna 150 airplane. If the combined distance traveled by these two small planes is 690 miles after 3 hours. What is the average speed of each plane? 
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Cessna 150 DATA:
rate = x mph; time = 3 hrs; distance = rt = 3x miles
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Piper Cub DATA:
rate = x+10 mph; time = 3 hrs; distance = rt = 3(x+10) = 3x+30 miles
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EQUATION:
distance + distance = 690 miles
3x + 3x+30 = 690
6x = 660
x= 110 mph (speed of the Cessna)
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x+10 = 120 mph (speed of the Piper Cub)
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Cheers,
Stan H.

3x + 
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