Question 762107
Let speed in still air be x.
Let wind speed be y.

While flying with wind, effective speed = {{{x + y = 500}}}
While flying against the wind, effective speed = {{{x - y = 440}}}

From eqn1, x = 500 - y

Substituting for x in eqn2, {{{500 - y - y = 440}}}

{{{2*y = 60}}} or {{{y = 30}}}

So {{{x = 500 - 30 = 470}}}

Speed of plane in still air is {{{highlight(470)}}} mph and wind speed is {{{highlight(30)}}} mph.

:)


This is similar to solved problem 761829 and many others - please check them out too.