p = 780 w = 180 You didn't provide a list of equations to select from, so let's see about creating them and solving. For this I'll use the variable p for the airspeed of the jet and w for the speed of the wind in the jet stream. So when the jet is traveling in the same direction as the jet stream, the ground speed is p+w and when the jet is traveling in the opposite direction, the ground speed is p-w. With that in mind, we can create two equations and solve them. The equations are: (1). 1920 = 2(p+w) (2). 1920 = 3.2(p-w) Let's take equation (1) above and distribute the 2. 1920 = 2(p+w) (3) 1920 = 2p + 2w And do the same for equation (2) above. 1920 = 3.2(p-w) (4) 1920 = 3.2p - 3.2w Let's multiply (3) above by 1.6 to make the w terms equal in magnitude and opposite in sign to that in equation (4) above. 1920 = 2p + 2w (5) 3072 = 3.2p + 3.2w Add (4) and (5) above together, then solve for p (4) 1920 = 3.2p - 3.2w (5) 3072 = 3.2p + 3.2w 4992 = 6.4p 780 = p So the Jet's speed is 780 km/h Now use the speed of the Jet and (1) above to get the wind speed. 1920 = 2(p+w) 1920 = 2(780+w) 960 = 780 + w 180 = w So the wind speed is 180.