The inner and outer surfaces of a 4-m × 7-m brick wall of thickness 30 cm and thermal cond...

The inner and outer surfaces of a 4-m × 7-m brick wall of thickness 30 cm and thermal conductivity 0.69 W/m ∙ K are maintained at temperatures of 20°C and 5°C. respectively. Determine the rate of heat transfer through the wall, in W.