What should i say about this at meps (cont). please help i need advice!?

like i said. i was busted in 9th grade with poss. or marijuana. the charge got dropped and i never had to do probation or service. what should i say when they ask at meps "have you done drugs" or "whats your criminial record like" becuase if i answered i got busted with poss. of mj they would automatically know that i had to have smoked it. which i did, but i was just messing around with friends.. never did it againn