Question 1000926

a plane traveled 580 miles to zambaouga and back. the trip there was with the wind. it took 5 hours. the trip back was against the wind. the trip back was 10 hours. find the speed of the plane in still air and the speed of the wind 
<pre>Let speed of plane in still air be S, and wind speed, W
With total speed with wind being 116 ({{{580/5}}}) mph, we get:
S + W = 116 ------- eq (i)
With total speed against wind being 58 ({{{580/10}}}) mph, we get:
S - W = 58 -------- eq (ii)
2S = 174 -------- Adding eqs (i) & (ii)
S, or speed of plane in still air = {{{174/2}}}, or {{{highlight_green(87)}}} mph