There were 3 men that rented a hotel room and it cost $30.00/night, split equally $10.00/each. The manager realizes they were overcharged $5.00, so she sends the bellboy with $5.00 and tells him to split it between the 3 men, the bellboy decides that it would be difficult to split 3 ways and puts $2.00 in his pocket, and gives each person a dollar, so between the 3 men they have now each spent $9.00, which altogether comes to $27.00... if you add that to the $2.00 the bellboy has that equals $29.00, where is the other dollar?

Motel Kept: $25
Stolen by bellhop: $2
Returned to men: $3
Equals $30

This "riddle" has been posted here several times. It's a fun problem to pose to kids - they'll often struggle with the misdirection of saying "27 + 2 =29" and not see that the correct situation is 27 - 2 = 25.

I have to confess, I was lazy:
https://www.google.com/search?q=There+were+3+men+that+rented+a+hotel+room +and+it+cost+%2430.00%2Fnight%2C+split+equally+%24 10&rls=com.microsoft:en-us:IE-Address&ie=UTF-8&oe=UTF-8&sourceid=ie7&rlz=1I7ADRA_enUS355