SOLUTION: A jet travels 2320 miles against a jetstream in 4 hours and 2760 miles with the jetstream in the same amount of time. What is the rate of the jet in still air and what is the rate

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: A jet travels 2320 miles against a jetstream in 4 hours and 2760 miles with the jetstream in the same amount of time. What is the rate of the jet in still air and what is the rate       Log On


   



Question 1185904: A jet travels 2320 miles against a jetstream in 4 hours and 2760 miles with the jetstream in the same amount of time. What is the rate of the jet in still air and what is the rate of the jetstream?
Found 2 solutions by greenestamps, josgarithmetic:
Answer by greenestamps(13216) About Me  (Show Source):
You can put this solution on YOUR website!


Speed against the wind: 2320/4=580mph

Speed with the wind: 2760/4=690mph

The 690mph is wind speed added to the plane speed; the 580mph is the wind speed subtracted from the plane speed.

That means the plane speed is halfway between 580 and 690mph, which is 635mph. Then the wind speed is the difference between 580 and 635mph (or the difference between 635 and 690mph), which is 55mph.

ANSWERS:
plane speed: 635mph
wind speed: 55mph

If you need formal algebra....

p=plane speed
w=wind speed
p+w=690
p-w=580
(add...)
2p=1270
p=1270/2=635
635+w=690
w=55


Answer by josgarithmetic(39630) About Me  (Show Source):
You can put this solution on YOUR website!
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A jet travels 2320 miles against a jetstream in 4 hours and 2760 miles with the jetstream in the same amount of time. What is the rate of the jet in still air and what is the rate of the jetstream?
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r, the jet speed
w, the wind stream speed
2320%2F4=r-w
and
2760%2F4=r%2Bw

system%28r-w=580%2Cr%2Bw=690%29------------Ready for Elimination Method