You are designing an underwater maintenance schedule for an offshore oil rig. The divers work at a depth of 15 m and the seawater density is 1027 kg m-3. They are known to consume 130 litres of air at the ambient temperature is 10oC over the time taken to do the job. Atmospheric pressure is 101325 Pa. Each full SCUBA diving tank contains 3 kg of air. What fraction of the tank air mass will be consumed on each job?