The Jet and the Wind

31)  Traveling from Dallas to Atlanta, a jet was able to average 760 mph, due
to a tailwind.  On the return flight, however, it averaged just 682 mph
against the same wind speed.  What was the speed of the wind, and what would
the speed of the jet have been if there were no wind?


        x = jet speed
        y = wind speed

        x + y = 760
        x - y = 682
        -----------
        2x =  1,442  (y variable cancels out)

         x = 721

         721 + y = 760  (The value of x is put into the equation to solve
                        for the value of y.)

         y = 39

         721 mph is the speed of the jet, and 39 mph the speed of the wind.