Physics Heat & Thermodynamics Level: Misc Level

The temperature in an electric oven is 163%C. The temperature at the outer surface in the kitchen is 54%C. The oven (surface area=1.5 m2) is insulated with material that has a thickness of 0.022 m and a thermal conductivity of 0.045 J/(s.m.%C).(a) How much energy is used to operate the oven for 7 hours?--J (b) At a price of $0.12 per kilowatt hour for electrical energy, what is the cost of operating the oven$--