<PRE><B>Question 338571</B>
An airplane whose speed through the air is 500 km/h covers a distance over the
 ground of 1000 km in 2.5 h. How fast was the wind against it?
:
Let w = speed of the wind
:
Write a dist equation: dist = time * speed
2.5(500-w) = 1000
1250 - 2.5w
-2.5w = 1000 - 1250
-2.5w = -250
w = {{{(-250)/(-2.5)}}}
w = +100 mph is the rate of the wind
;
:
Check solution find the distance: 2.5(500 - 100) = 1000
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