A real question, one with a question mark?
Answer:

Explanation:
v = Velocity of the breeze = 4 m/s
w = Width of the valley = 5000 m
h = Height of the valley = 1000 m
Volumetric flow rate is given by

= Mass flow rate of pollutant = 25 g/s = 
Concentration is given by

The steady state concentration of pollutants in the valley, is
.
23.5 DEGREES is the answer.
The other 4 kg of mass may have departed the scene
of the fire, in the form of gases and smoke particles.