1. The problem statement, all variables and given/known data Consider the following multi-layer wall consisting of an interior insulation layer and an external light-weight concrete layer. Calculate the heat flow thorugh the structure and the temperature at the interface between the two materials. Layer 1: Thermal insulation; Thickness (d): 100mm; λ: 0.033W/mK Layer 2: Light-weight concrete; Thickness (d): 100mm; λ: 0.14W/mK 2. Relevant equations Heat flow: Q=K*(T1-T2) [W] (But no temperature is given in the question) Conductance: K=λ*A/d 3. The attempt at a solution I don't know how to get there but the answer is Q=40.1W and Tm=-4.3C°. I don't know which equations to use because there is no temperature nor wall area given in the question.