The Missing Dollar

Three travelers register at a hotel and are told that their rooms will cost $10 each so they pay $30. Later the clerk realizes that he made a mistake and should have only charged them $25. He gives a bellboy $5 to return to them but the bellboy is dishonest and gives them each only $1, keeping $2 for himself.

So the men actually spent $27 and the bellboy kept $2.What happened to the other dollar of the original $30?

Here it is found! 

Source 

The Story of Dollar That Wasn't Lost

How it was lost? 

All you need to think on the behalf of travelers to simplify things around.

Initially they spent $30 for the stay. Now these $30 distributed into 2 parts viz. 25 & 5 by clerk.  Out of 5, travelers received only 3 that means now they have spent $27 only. Out of 27, clerk had 25 & bellboy took 2! Trying to add bellboy's 2 in 27 is pointless but the base of this quiz!