Fun Mathy Type Riddles

[Whateverist]

My favorite as a child was this (it confused the heck outta me back then):

Three people check into a hotel room. The clerk says the bill is $30, so each guest pays $10. Later the clerk realizes the bill should only be $25. To rectify this, he gives the bellhop $5 to return to the guests. On the way to the room, the bellhop realizes that he cannot divide the money equally. As the guests didn't know the total of the revised bill, the bellhop decides to just give each guest $1 and keep $2 as a tip for himself. Each guest got $1 back, so now each guest only paid $9, bringing the total paid to $27. The bellhop has $2. And $27 + $2 = $29 so, if the guests originally handed over $30, what happened to the remaining $1?

I used to give this one out to bedevil middle schoolers.

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The $2 the bell hop kept along with $3 that was returned to the guests and the actual $25 cost of the room correctly total to the $30 they originally paid.

It is true but irrelevant that $27 + $2 = $29.  $27 is the actual amount of money they paid, and that is equal to the actual cost of the room plus the money the bell hop took,  $25 + $2 = $27.  The money the bell hop took is part of what the $27 went toward, adding $2 to the $27 again doesn't make any sense.  There is no missing dollar.

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Here is another:

A man looking at a photo of someone muses, I am an only child yet that man*'s father is my father's son. Whose photo is the man looking at?

*He is referring to the man in the photo he is looking at.

I confess I screwed with the wording to foil google searches .. I hope.