Question 364095
Let x = the speed of wind in mph

distance = airspeed x travel time
         = airspeed x travel time from San Francisco to New York
         = airspeed x travel time from New York to San Francisco

550 * 5 = (550-x-x) * 6
 2750   = 3300 - 12x
 12x    = 3300 - 2750
 12x    = 550
   x    = 45.83 

The speed of wind is 45.83 mph