I feel like I must be missing something really obvious but I can't understand how to figure out these mole fractions without any information in terms of pressure etc.
Can you please help me walk through the steps-
5. Trimix is used for very deep diving. It is composed of three gases, usually helium, nitrogen and oxygen. The composition is denoted as percentage of oxygen / percentage of helium, e.g. 17/50 is Trimix with 17.0% oxygen, 50.0% helium and the rest is nitrogen. Assuming these as mass percents, calculate the mole fraction of each gas in the mixture.