<PRE><B>Question 529189</B>
a plane took 4 h to fly 2200 km from saskatoon to toronto with a tail wind.
The return trip,with a head wind,took 5 h.
Find the speed of the plane in still air and the wind speed 
:
Let s = the speed of the plane
Let w = speed of the wind
then
(s+w) = effective speed with the wind
and
(s-w) = effective speed against the wind
:
Write a distance equation for each trip, dist = speed * time
:
5(s-w) = 2200
4(s+w) = 2200
Simplify, divide the 1st equation by 5, the 2nd equation by 4, results
s - w = 440
s + w = 550
-----------adding eliminates w, find s
2s = 990
s = {{{990/2}}}
s = 495 mph is the speed of the plane
and
495 + w = 550
w = 550 - 495
w = 55 mph is speed of the wind
:
:
Check solution in the original 1st equation
5(495 - 55) = 
5(440) = 2200</PRE>