I was told this riddle by my brother, who coincidentally, did not know the answer insofar as the person who told it to him didn’t know it either. I think I’ve figured it out, but I thought it might be more enlightening (and more than a bit entertaining) to see what the teeming millions would have to say about it.

Three brothers check into a hotel. The new clerk on duty told them the room would be \$30 for the night. Each brother paid \$10 and they went to their room. The hotel manager, who had been to lunch, came back and reminded the new clerk that due to special they were running, the room was supposed to be only \$25. He gave the clerk \$5 with instructions to return it to the brothers in their room. He knocked on the door and explained the situation to the three brothers and offered them the \$5 refund. They said rather than bother splitting the refund three ways, that the clerk should just give them a dollar each and keep the other two himself, which the clerk did.

This means each brother paid \$9 out of pocket. 3 times 9 is 27, and the 2 the clerk kept makes \$29. So where did the other dollar go?

Please do not simply restate the problem in some other way so that it all adds up. Rather, try to identify the reason the math doesn’t add up when the problem is posed in this way.

Thanks to all.

This has been done to death. Look here for the answer:

Snopes - Dollar disappears during motel transaction.

Great!!! :smack:

First guy out of the box knows the answer! So much for entertainment.

This may have been done to death but no one I’ve occasionally posed it to in the last 20 years has heard it or been able to figure it out.

Thanks to Desmostylus for the link.

While we’re here, may I just say that yes, a duck’s quack does echo, and there is no third ~gry word.

Er… sorry, Mangetout, I’m not looking for the answer of the third ~gry word, but, would you tell me what is the riddle? (no joking).

The \$9 paid by each person INCLUDES the \$2 kept by the clerk, it’s the \$3 he gave them back that is added to the \$9x3=\$27 (\$27+\$3=\$30)

Spelling and grammer subject to change without notice

This gets me every time, but I can sort of get my head round it.

The men paid out \$30 originally.

Getting a dollar each back, they paid out only \$27.

This comprises the \$25 for the room, and the \$2 for the clerk.

I find it helps to remember the explanation if you visualize the money.

See 30 dollars go into the register. Then see 5 dollars go out and 25 remain. Then see 3 in the hands of the men, 2 in the pocket of the bellboy, and 25 in the register. Then, when you are asked to account for the 30 dollars, it becomes obvious that you are being asked to add the same 2 dollars which are already included in the 27 instead of the 3 held by the men.

Finding the answer is only part of the fun of this puzzle. Another part is the fun of crafting a memorable explanation. Long live the “missing dollar puzzle”!

That’s why accounting turn out to be a science (cash, bank, debts, etc). It solves those kind of problems.

Thanx everyone. I was just about to pose the same question but thought I’d do a quick search first. I liked Ex Machina’s explanation best. Very helpful. What a much nicer world it would be if people helped each other more… (feeling warm & fuzzy)