Given :
Initial pressure, [tex]P_i=200\ kPa[/tex].
Initial volume, [tex]V_i= 4\ m^3[/tex].
Final volume, [tex]V_f = 2 \ m^3[/tex].
To Find :
Final pressure, [tex]P_f[/tex].
Solution :
We know, at constant temperature :
[tex]P_iV_i=P_fV_f\\\\P_f=\dfrac{P_iV_i}{V_f}\\\\P_f=\dfrac{200\times 4}{2}\\\\P_f=400\ kPa[/tex]
Therefore, new pressure is 400 kPa.
Hence, this is the required solution.