You go to the doctor and he gives you 12 milligrams of radioactive dye. After 24 minutes, 8 milligrams of dye remain in your system.

You go to the doctor and he gives you 12 milligrams of radioactive dye. After 24 minutes, 8 milligrams of dye remain in your system. To leave the doctor's office, you must pass through a radiation detector without sounding the alarm. If the detector will sound the alarm if more than 2 milligrams of the dye are in your system, how long will your visit to the doctor take, assuming you were given the dye as soon as you arrived?