mixing process

A girl mixes hot water at 90°C with cool water at 5°C. It is most pleasurable to have a cup of warm water at that time, so she mixes 0.2kg of hot water to 0.3 kg of cool water. Determine the exergies of the hot water, the cold water, and the final mixture, as well as the irreversibility of the mixing process, assuming that it is done in a mug that is adiabatic. The pressure throughout is atmospheric and the ambient temperature is 22°C.