How long 120mg. well, the half-life of methadone can be up to 59-hours, so after 2 and half days you would still have 60mg's in your system. But this doesn't take into account multiple doses.
A third type of lock is a security lock. This lock is like a typical password, to prevent someone other than the owner from using the phone. If activated accidentally, the user manual or carrier customer service can usually tell you the default code.
Add, remove, or change iPad password (Enable or disable passcode protection). By default, your iPad locks itself after a certain period of inactivity (5 minutes, but you can customize your iPad Auto-Lock settings).