Will you pass a drug test if you smoked half a joint and you will have to be drug tested in 16 days?

You probably will not. Depends on a few things.

1. How much fat you have and how fast your metabolism is. Your fat cells store the THC.

2. How much you smoke.

Working out can help but if you do it for the couple of days before the test, it can end up sending more THC into the blood which will trigger the test. Of course, the safest way to pass a drug test is to not do drugs.