3 dost hotel me khana khanay gaye...

3 dost hotel me khana khanay gaye.Teeno ne dus dus rupay yani Total 30 rupay bill ke liye waiter ko diye.
Waiter ne us mein se 25 rupay khanay ke katay.Bqaya 5 rupay mein se 2 rupay khud rakhay.
Or 3 rupay mein se ek ek rupya teeno doston ko de dya.
Is trah teeno doston ne no no(9,9,9) rupay dye.
Khanay ke liye is trah total 27 rupay dye gaye - 2 rupay waiter ne rakhay.
27+2=Rs.29
Baqi ek rupya kahan gya???