At a temperature of 27.0C, what is the speed of longitudinal waves in (a) Hydrogen molar mass

Question:

At a temperature of 27.0°C, what is the speed of longitudinal waves in
(a) Hydrogen molar mass 2.02 g/mol)?
(b) Helium (molar mass 4.00 g/mol);
(c) Argon (molar mass 39.9 g/mol)? See Table 19.1 for values of 'Y.
(d) Compare your answers for parts (a), (b), and (c) with the speed in air at the same temperature.