3 guys entered a restaurant , when they asked for the check it was 30$ , so logicaly each one is going to pay 10 $ and they did , but because the owner of the restaurant knows one of the guys he gave him back 5 $ , and this guy decided to give each of his friends 1 $ , he kept one dollar and gave the waiter 2$ tip . THE QUESTION IS : IF EACH ONE PAYED 10$ AND GOT 1$ BACK SO EACH ONE PAYED 9$ RIGHT , 3*9=27 + THE 2$ TIP THATS 29 , SO WHERE IS THE MISSING DOLLAR ??????!!!!!!!!!!