Question

An airplane flies 490 miles with the wind and 350 miles against the wind in the same length
of time. If the speed of the wind is a fixed 40 mph, what is the speed of the airplane in still
air?

I feel stupid.. can someone explain this to me?

Answer 1

OMG! AN AMBASSADOR LIKES ANIME!

Answer 2

Distance = rate x time
Distance/Time = Rate

"An airplane flies 490 miles with the wind and 350 miles against the wind in the same length
of time. If the speed of the wind is a fixed 40 mph, what is the speed of the airplane in still
air?"

490/40 - wind = 350/40 + wind

Or, in other words...
\[\frac{ 490 }{ 40 - r } = \frac{ 350 }{ 40 + r}\]

Answer 3

Solving for r wille give you the plan in still air

Answer 4

@Compassionate

I'm flying against the wind myself tonight.
I don't follow how the posted equation gives the plane speed in still air.

What does the variable r represent?

Attached are the problem options.

Answer 5

r is just the plane in still air. I jjust picked that variable.