A heat pump provides 125000 kJ/h of heat, keeping a house at 25C. The heat pump is planned to operate for 120 hours per month. Consider that this heat pump draws heat from two different external sources. Let it take heat from the outside environment at 0C in the first case, and from a nearby lake at 10C in the second case. According to this, calculate

a) The amount of heat withdrawn in a month from the low temperature environment for both cases (kJ),

b) Since the unit price of electricity is 0.55 TL/kWh, the lake should be used as an external heat source. the amount of money saved monthly,

c) If this heating process is carried out using an electric heater, monthly Calculate the heating cost.