Actually, THC stays in your system longer than most drugs (go figure), and if you have to "drop" (urine test) for your probation within 6 days of smoking, you are kinda screwed. THC stays in your fatty tissue for 30 days (sometimes longer if you are a heavy smoker (Go figure again). This would also depend on how much you smoked. If you just smoked that one time only, you have a chance of testing clean, but there is also the chance you wouldn't. I once had to take a urine test (for my job) after smoking quite a bit before, and I drank a lot of water, but also bought a herbal tea (Forgot the name) that helped me. Mine wasn't a "positive / negative" test, and I was allowed to have a certain amount in my system (tested positive, but which I didn't go over the maximum allowed). You really need to try to get up the $$$ to buy this tea, which is around $30.00 (I think), and you can get it at mostly any herbal store...including GNC. Ask the sales person what the name is...they should know. I know probation uses a "positive / negative test", and also tests for amounts, so you might get away with telling your probation officer that you were in a closed in space when other people were smoking, and that you must have gotten some in your system from the 2nd hand smoke. If he is not a jerk, he might let you slide. Also, probation usually uses a urine test, as hair and blood testing are a lot more expensive than urine testing. Good Luck!!!!
THC is called Tetrahydrocannabinol present in narcotic analgesics. It can be eliminated from the system with in one week but from hair follicle it will take 100 days to get out.