A very large container consists of an ideal gas. The speed of sound...

The speed of sound in an ideal gas is given by the formula $v = \sqrt{\dfrac{\gamma R T}{M}}$.

Since the temperature $T$ is kept constant and the gas remains the same, the values of $\gamma$, $R$, $T$, and $M$ are all constant.

Therefore, the speed of sound is independent of the pressure of the gas as long as the temperature is constant. Alternatively, using $v = \sqrt{\dfrac{\gamma P}{\rho}}$, when the pressure $P$ is doubled at constant temperature, the density $\rho$ also doubles, keeping the ratio $\dfrac{P}{\rho}$ constant.

Thus, the new speed of sound $y$ is equal to the initial speed of sound $x$.

The ratio $\dfrac{x}{y} = 1$.

Answer: $1$