On May 20, 10:49*am, pilot27usa pilot27usa.
wrote:
A plane flies 450 miles with the wind and 300 miles against the wind in
the same length of time. If the speed of the wind is 20mph, what's the
speed of the plane in still air?

a) 90mph
b) 105mph
c) 100mph
d) 125mph

Is there a formula to solve this? I am just a student pilot, but it
seens to me like I would need the time and heading to solve this!? Am I
wrong?
Thank you guys.

Probably not the best forum, because a pilot's solution (especially
were this to pop up on a written exam) would probably be to run each
of the numbers through an E6B and eliminate each option, which is
quicker and easier to do on a mechanical E6B than it is to figure out
the formula on the fly, especially since it's not particularly
relevant to flight planning. This is a math question. :