The wall of a pipe of radius 1 m is at a uniform temperature of 200 °C, and is covered by insulation of thickness 0.1 m.
The ambient air outside the insulated pipe is at 20 °C and has heat transfer coefficient of 10 W m⁻² K⁻¹.
The thermal conductivity of the insulation material is 0.05 W m⁻¹ K⁻¹.
If the heat transfer occurs at steady state, the temperature (in °C) of the outer surface of insulation is __________ (rounded off to second decimal place).