SOLUTION: An airplane averages 150 mph. If a trip from Atlanta to Charleston takes 2 hours 48 minutes going against the wind, and 2 hours on on the return flight going with the wind, what is
Question 1197567: An airplane averages 150 mph. If a trip from Atlanta to Charleston takes 2 hours 48 minutes going against the wind, and 2 hours on on the return flight going with the wind, what is the speed of the wind Found 4 solutions by math_tutor2020, greenestamps, josgarithmetic, ikleyn:Answer by math_tutor2020(3817) (Show Source): You can put this solution on YOUR website!
w = speed of the wind in mph
2 hrs + 48 min = 2 hrs + (48/60) hrs
2 hrs + 48 min = 2 hrs + 0.8 hrs
2 hrs + 48 min = 2.8 hrs
150-w = speed of the plane going against the wind
distance = rate*time
distance = (150-w)*2.8
distance = 420-2.8w
150+w = speed of the plane going with the wind
distance = rate*time
distance = (150+w)*2
distance = 300+2w
The distance is same each time because the plane is following the same route, when going from Atlanta to Charleston then back from Charleston to Atlanta.
Because the distance is the same for each equation, we can equate the right hand sides and solve for w.
420-2.8w = 300+2w
420-300 = 2w+2.8w
120 = 4.8w
w = 120/4.8
w = 25
The speed of the wind is 25 mph
Check:
If the plane goes against the wind, then its speed is 150-w = 150-25 = 125 mph.
Traveling for 2.8 hours means it covers a distance of 125*2.8 = 350 miles
If the plane goes with the wind, then its speed is 150+w = 150+25 = 175 mph.
Traveling for 2 hours gives a distance of 175*2 = 350 miles.
We get the same distance each time to help confirm the answer.
Here is a very unorthodox solution method -- in case you are interested in looking at alternatives.
Let x be the speed of the wind; then the plane's speeds are 150+x with the wind and 150-x against the wind.
The distances are the same, so the ratio of speeds is the reciprocal of the ratio of the times. The ratio of the two times in minutes is 168/120 = 7/5. So
The solution by @josgarithmetic is conceptually TOTALLY wrong.
It is wrong, since this airplane averages 150 mph in STILL AIR
(the part of the condition, which is in the post).
Again : 150 mph is the average speed of the plane in STILL AIR,
but NOT IN THIS round trip: 150 mph relates to TOTALLY DIFFERENT conception.
The post itself has a HUGE DEFICIENCY: it missed
to determine correctly all the participating values/conditions.
Taking it into the consideration, the problem, as it is worded in the post,
is ambiguous, which is not allowed for Math problems.
Therefore, my advise to the visitor is to throw this " problem " to the closest garbage bin
and to that only mathematically correct problems are the subject of consideration at this forum.
Each correct mathematical problem is a piece of art.
What is not piece of art - is not a correct mathematical problem.
Exactly as the wife of an emperor should be beyond suspicions,
every Math problem must be ideally and absolutely correct - always.