Question 141075
let p=plane and w=wind


"When a plane flies into the wind, it can travel 3000km in 6 hours"
__ p-w=3000/6 __ p-w=500


"When it flies with the wind, it can travel the same distance in 5 hours"
__ p+w=3000/5 __ p+w=600


adding the two equations __ p-w+(p+w)=500+600 __ 2p=1100 __ p=550


substituting __ 550+w=600 __ w=50