Thermodynamic Processes question from MHT CET 2021 (24 Sep, Shift 1)

An ideal gas with pressure $P$, volume $V$ and temperature $T$ is expanded isothermally to a volume $2\,V$ and a final pressure $P_i$. The same gas is expanded adiabatically to a volume $2\,V$, the final pressure is $P_a$. In terms of the ratio of the two specific heats for the gas '$\gamma$', the ratio $\frac{P_i}{P_a}$ is