A closed vessel contains \( 10 \, \text{g} \) of an ideal gas \( X \) at \( 300 \, \text{K} \), which exerts \( 2 \, \text{atm} \) pressure. At the same temperature, \( 80 \, \text{g} \) of another ideal gas \( Y \) is added to it and the pressure becomes \( 6 \, \text{atm} \). The ratio of root mean square velocities of \( X \) and \( Y \) at \( 300 \, \text{K} \) is:
