Question 215846
An executive flew in the corporate jet to a meeting in a city 1500 kilometers away. 
After traveling the same amount of time on the return flight, the pilot mentioned
 that they still had 300 kilometers to go. 
The air speed of the plane was 600 kilometers per hour. 
How fast was the wind blowing? (Assume that the wind direction was parallel to
 the flight path and constant all day.)
: 
we can summarize this problem with a statement that:
"It took the same amt of time to fly 1500 km with the wind, as it did to fly 1200 mi against the wind"
:
let w = speed of the wind
then
(600+w) = ground speed with the wind
and
(600-w) = ground speed against the wind
;
Write a time equation (time - dist/speed):
{{{1200/((600-w))}}} = {{{1500/((600+w))}}}
Cross multiply
1200(600+w) = 1500(600-w)
:
720000 + 1200w = 900000 - 1500x
:
1200w + 1500w = 900000 - 720000
;
2700w = 180000
w = {{{180000/2700}}}
w = 66{{{2/3}}} km/hr the speed of the wind
:
:
Check solution by finding the times of each flight
{{{1500/666.67}}} = 2.25 hrs
{{{1200/533.33}}} = 2.25 hrs, confirms our solution