<PRE><B>Question 279493</B>
A plane can fly at a rate of 150 mph in calm air. Traveling with the wind, the plane flew 700 miles in the same amount of time as it flew 500 miles against the wind. Find the rate of the wind.

let wind speed be x

700 / x+150 = time taken with the wind

500 / 150-x  = time taken against wind

the tiems are ssame.

700/150+x = 500 / 150-x

700(150-x) = 500( 150+x)

105000 -700x=75000+500x

1200x= 30000

x=25 mph





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