b$)$ A chimney of $1\mathrm{.}8$ m diameter fitted with a certain thermal power plant produces a draught equal to $18$ mm water column. The mean temperature of flue gases is $270\backslash$deg C and the boiler house temperature is $32\backslash$deg C$.$ If the flue gases formed per kg of fuel burnt are $22,$ make calculations for the mass of flue gases passing through the chimney.