An insulation system around a cylindrical pipe consists of two different layers. The first layer immediately on the outer surface of the pipe is made of glass wool and the second one is constructed using plaster of Paris. The pipe diameter is \(10 \mathrm{~cm}\) and each insulating layers is \(1 \mathrm{~cm}\) thick. The thermal conductivity of the glass wool is \(0.04 \mathrm{~W} / \mathrm{m}^{\circ} \mathrm{C}\) and that of the plaster is \(0.06 \mathrm{~W} / \mathrm{m}^{\circ} \mathrm{C}\). The pipe carries hot oil at a temperature of \(92^{\circ} \mathrm{C}\) and the atmospheric temperature, outside is \(15^{\circ} \mathrm{C}\). If the heat transfer coefficient from the outer surface of the insulation to the atmosphere is \(15 \mathrm{~W} / \mathrm{m}^{2}{ }^{\circ} \mathrm{C}\), calculate the temperature at the interface between the two insulating materials and on the outer surface (neglect pipe wall thickness).