The correct options are
A The pressure in the two compartments are equal.
B Volume of compartment I is 3V/5.
C Volume of compartment II is 12V/5.
D Temperature in both the compartment will be equal.
In the equilibrium position, the net force on the partition will be zero.
Hence pressure on both sides is same,
Therefore, (a) is correct.
n1=P1V1RT1=PVRT
n2=(2P)(2V)RT=4PVRT⇒n2=4n1
Moles remain conserved.
Finally pressure becomes equal in both the parts. Since, conducting partition is present, therefore temperature in both the compartment will become equal. Therefore, option (d) is also correct.
Using, P1V1=n1RT1,
P2V2=n2RT2,
P1=P2 and T1=T2
V1V2=n1n2=14
V2=4V1
Also, V1+V2=3V⇒V1+4V1=3V
V1=35V and V2=125V
Hence, options (b) and (c) are correct.