Question 912340
The rate of the jet stream is 100 miles per hour. Traveling with the jet stream, an airplane can fly 800 miles in the same amount of time as it takes to fly 600 miles against the jet stream. What is the airplane's average rate in calm air?
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let x=rate of plane in calm air
x+100=rate of plane with jet stream
x-100=rate of plane against jet stream
travel time=distance/rate
..
{{{800/(x+100)=600/(x-100)}}}
600x+60000=800x-80000
200x=140000
x=700
What is the airplane's average rate in calm air? 700 mph