Concept:
For isothermal process:
\[
PV=\text{constant}
\]
For adiabatic process:
\[
PV^\gamma=\text{constant}
\]
Since \(\gamma>1\), pressure rises faster in adiabatic compression.
Step 1: Pressure in isothermal compression.
\[
P_A V_i=P'_A \frac{V_i}{2}
\]
\[
P'_A=2P
\]
Step 2: Pressure in adiabatic compression.
\[
PV^\gamma=P'_B\left(\frac V2\right)^\gamma
\]
\[
P'_B=P2^\gamma
\]
Since:
\[
2^\gamma>2
\]
therefore,
\[
P'_B>P'_A
\]
Thus pressure of gas \(A\) is less.
Hence,
\[
\boxed{\text{Final pressure of A is less than that of B}}
\]