The original problem:
Three guests
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 for himself.
Now that each of the guests has been given $1 back, each has paid $9,
bringing the total paid to $27. The bellhop has $2. If the guests
originally handed over $30, what happened to the remaining $1?
The followup solution:
A few months later, two of the original three guests check into a hotel
room in the same hotel. The clerk says the bill is $20, so each guest
pays $10. Later the clerk realizes the bill should only be $15. 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 $3 for himself.
Now that each of the guests has been given $1 back, each has paid $9,
bringing the total paid to $18. The bellhop has $3, so $18 + $3 = $21,
and the guests originally handed over $20, so that's where the missing
dollar from the original problem is!
