A 230V electric water heater takes water at a mean temperature of 16°C and the mean temperature of the outlet water is 82°C. The cost at 0.2p per unit of the energy it consumes in a given period is 74.4p. Determine the quantity of water used if the efficiency of the heater is 80 per cent. Take the specific heat capacity of water as 4.2kJ/kg°C.

A 230V electric water heater takes water at a mean temperature of 16°C and the mean temperature of the outlet water is 82°C. The cost at 0.2p per unit of the energy it consumes in a given period is 74.4p. Determine the quantity of water used if the efficiency of the heater is 80 per cent. Take the specific heat capacity of water as 4.2kJ/kg°C.