A furnace wall is composed of three layers: 15 cm of firebrick [k = 1.5 W/(m*K)], followed by 22.5 cm of kaolin insulation brick [k = 0.075 W/(m*K)], and finally followed by 4 cm of masonry brick [k =1.0 W/(m*K)]. The temperature of the inner wall surface (firebrick) is 1400 K and the outer surface (masonry brick) is at 350 K. Assume that each layer has an area normal to the direction of heat flow equal to 1 m2. What is the temperature at the firebrick-kaolin interface? What is the temperature at the kaolin-masonry interface? Across what material is the temperature drop the highest?