Physics Puzzler
07-06-2006 | 09:15 AM
#1
Thread Starter
Senior Member
Joined: Oct 2002
Posts: 2,065
Likes: 0
Received 0 Likes
on
0 Posts
From: Philadelphia,
PA
Physics Puzzler
Many decades ago I read a series of science puzzles in Scientific American magazine and one of them has stuck with me as I don't know the answer. Take a metal disk with a hole in the center, like a washer. Heat the disk and the outside diameter increases. What happens to the inside diameter? Does anyone have a certain answer?
07-21-2006 | 07:14 AM
#4
Senior Member
My Feedback: (4)
RE: Physics Puzzler
Ok, then let this one keep you awake for a while:
You go on a trip with two other guys.
You get a hotel room. The kid behind the desk says the room is $30 a night. So you each pay $10.
Later, the manager reminds the kid that this week they have a $25 special, so he over charged them and to give them back $5
On the way to the room, the kid figures, "$5 doesn't split equally between 3 guys" so he pockets $2 and gives them back a dollar each.
Now here's the problem... Now the guys only paid $9 each - That's $27. Plus the two that the kid put in his pocket equals $29
Where did the other dollar go???
You go on a trip with two other guys.
You get a hotel room. The kid behind the desk says the room is $30 a night. So you each pay $10.
Later, the manager reminds the kid that this week they have a $25 special, so he over charged them and to give them back $5
On the way to the room, the kid figures, "$5 doesn't split equally between 3 guys" so he pockets $2 and gives them back a dollar each.
Now here's the problem... Now the guys only paid $9 each - That's $27. Plus the two that the kid put in his pocket equals $29
Where did the other dollar go???
07-21-2006 | 08:11 AM
#5
RE: Physics Puzzler
ORIGINAL: MinnFlyer
Ok, then let this one keep you awake for a while:
You go on a trip with two other guys.
You get a hotel room. The kid behind the desk says the room is $30 a night. So you each pay $10.
Later, the manager reminds the kid that this week they have a $25 special, so he over charged them and to give them back $5
On the way to the room, the kid figures, "$5 doesn't split equally between 3 guys" so he pockets $2 and gives them back a dollar each.
Now here's the problem... Now the guys only paid $9 each - That's $27. Plus the two that the kid put in his pocket equals $29
Where did the other dollar go???
Ok, then let this one keep you awake for a while:
You go on a trip with two other guys.
You get a hotel room. The kid behind the desk says the room is $30 a night. So you each pay $10.
Later, the manager reminds the kid that this week they have a $25 special, so he over charged them and to give them back $5
On the way to the room, the kid figures, "$5 doesn't split equally between 3 guys" so he pockets $2 and gives them back a dollar each.
Now here's the problem... Now the guys only paid $9 each - That's $27. Plus the two that the kid put in his pocket equals $29
Where did the other dollar go???
the guyes gave the hotel 3x $9 or $27 the clerk kept $2 so $27 to the hotel, less the $2 the kid kept is the $25 in the till.
07-25-2006 | 10:25 PM
#6
Senior Member
My Feedback: (8)
Joined: Apr 2002
Posts: 1,398
Likes: 0
Received 0 Likes
on
0 Posts
From: Silverdale,
WA
RE: Physics Puzzler
$25 doesn't divide evenly between 3 people, it comes to about $8.33. Give a buck back to each of the customers, and they have effectively paid $9.33 which rounds just about equals $28 ($27.99).
07-28-2006 | 10:24 PM
#7
RE: Physics Puzzler
MinnFlyer's problem was first told to me by my Dad when I was a grade school kid. (I'm 70 now)
There are a number of explanations however as presented, the $1 is definitely a mystery.
If I lay down $10 and I receive $1 back, I have paid $9. True even in the new math!
At a party, it makes for a good conversation item after a few beers.
There are a number of explanations however as presented, the $1 is definitely a mystery.
If I lay down $10 and I receive $1 back, I have paid $9. True even in the new math!
At a party, it makes for a good conversation item after a few beers.
08-01-2006 | 09:22 AM
#9
RE: Physics Puzzler
ORIGINAL: Hossfly
If I lay down $10 and I receive $1 back, I have paid $9. True even in the new math!
If I lay down $10 and I receive $1 back, I have paid $9. True even in the new math!
$30 out of their pockets into th hotel drawer
-$3 back to them leaves
$27, minus the $2 to the clerk
leaves $25 in the hotel drawer.
