A Slab of Insulation Is Made of Three Layers, as Drawing

Multiple Choice

A slab of insulation is made of three layers, as Drawing I indicates. Each of the layers A, B, and C has the same thickness, but a different thermal conductivity. Heat flows through the slab, and the temperatures are as shown. What are the temperatures T₁ and T₂ in Drawing II where the layers are arranged in a different order?

A) T₁ = 230 °C and T₂ = 170 °C
B) T₁ = 200 °C and T₂ = 180 °C
C) T₁ = 220 °C and T₂ = 160 °C
D) T₁ = 180 °C and T₂ = 160 °C
E) T₁ = 210 °C and T₂ = 190 °C