Hello!
To solve this problem, we will use the Boyle's Law, which describes how pressure changes when volume changes and vice-versa. The equation for this law is the following one, and we'll clear for V2:
[tex]P1*V1=P2*V2 \\ \\ V2= \frac{P1*V1}{P2}= \frac{3,24 L * 1 atm}{1,20 atm}= 2,7 L [/tex]
So, the final volume after increasing the pressure would be 2,7 L. That means that volume decreases when the pressure increases
Have a nice day!