Answer:
It would take the plane about 4.17 hours to fly the whole round trip.
Step-by-step explanation:
Assuming that the distance from Chicago to Boston is 2000/2 = 1000 miles.
Since the wind is blowing from Chicago to Boston, when the plane is traveling to Boston, the velocity of the wind adds to the its velocity:
;
therefore, the time it takes for the plane to go from Chicago to Boston is


Now, as the plane flies back from Boston to Chicago, the wind is blowing opposite the direction of its movement; therefore, the wind's velocity subtracts from the velocity of the plane:

and the time taken during the trip is


Therefore, the total time taken
during the whole round trip is


Therefore, on the windy day, it would take the plane 4.17 hours to fly the whole round trip