Question 1154738
Speed of airplane when no wind, r
Speed of the wind, w


WITH the wind, speed was {{{680/2=340=r+w}}}.


AGAINST the wind, speed was {{{680/(2&1/2)=272=r-w}}}.


Solve this system, using Elimination Method if you wish:
{{{system(r+w=340,r-w=272)}}}