The plane is flying exactly to the east at a speed of 250 m / s relative to the ground while the south wind is blowing

The plane is flying exactly to the east at a speed of 250 m / s relative to the ground while the south wind is blowing. Aircraft speed relative to air is 253 m / s. In this case, the wind speed relative to the ground is?

Because the airplane speed vector and the wind speed vector relative to the ground are perpendicular, then you can use the Pythagoras theorem:
V² = V1² + V2², where V is the speed of the aircraft relative to the air (V = 253 m / s), V1 is the speed of the aircraft (V = 250 m / s), V2 is the wind speed relative to the ground (m / s).
V² = V1² + V2².
V2² = V² – V1².
V2 = sqrt (V² – V1²) = sqrt (253² – 250²) = sqrt (64009 -62500) = sqrt (1509) = 38.85 m / s.
Answer: The wind speed over the ground is 38.85 m / s.