Underwater, the pressure rise by 1 bar for every 33 feet of depth. Deep sea divers habitually breathe a mixture of gases that is depleted in oxygen in order to avoid oxygen toxicity, which can take place when the partial pressure of O2 exceeds 1.4bar. Explain what is the maximum mole percent of O2 in a mixture that could be utilized by divers at depths up to 190.0 feet?