You should be ok, however, how long a drug stays in your system can vary depending on amount and frequency of use, metabolic rate, body mass, age, overall health, drug tolerance and urine pH, so there's no way to know for sure.
If the Percocet was prescribed for you, all you have to do is take the prescription bottle with you to the drug test and there should be no problem. For more information about drug screenings, read: "Passing" Those Drug Screenings
No way! You have to wait at least three days! I know because I take these tests ALL the time! for two years now!
For 24 hours a Drug Test will show a trace of it in your system.