What is the total pressure on the gas after the 760 mm Hg has been added?

Question

FIRST PHASE
atmospheric pressure= 760 torr
gas volume= 60 mL
(760 mm Hg added to 2nd phase)

SECOND PHASE
atmospheric pressure= 760 torr
Gas volume= 30 mL

**image looks like a J. in the 2nd phase, there is 760 mm that is half of the J** if that makes any sense.
I am confused on how you solve the problem considering the torr and ml and mm and mmHg