>The composite wall consists of three materials with area is 1 m, two of which are of known thermal conductivity, kA-20W/m.C and ke-50W/m.C, and known thickness, LA-0.3 m and Le-0.15 m. The third material, B, which is sandwiched between material A and C, is of known thickness, LB-0.15 m, but unknown thermal conductivity ka. Under steady state operating conditions, measurements reveal an outer surface temperature of Txo-20C, an inner surface temperature of T-600C, the equivalent thermal resistance of the wall is 0.024 C/W. Answer the following questions below Q18) What is the heat transfer rate through the wall in (kW)? A) 19.64 C) 24.17 E) None of them. B) 21.54 D) 22.49 Q19) What is the thermal conductivity of material B in (W/m.C)? A) 25.0 C) 18.75 E) None of them. A) 276.9 B) 23.18 D) 15.48 Q20) What is the temperature between material A&B in (C)? C) 245.15 B) 237.45 D) 200.5 Air E) None of them. TJ KA ka kc To LA KEY 2