# A weighty problem...

skeeter
Posers and Puzzles 20 Sep '03 21:18
1. skeeter
515 + 30 days
20 Sep '03 21:18
Ok , this is an oldie but a goodie

You have eight identical looking balls but one of them is heavier than the others in this set. Using ONLY a set of balance scales and with ONLY two weighings how does one discover which ball is the heaviest in the set. under 1 minute = einstein. 1 - 5 mins = brilliant . 5 - 10 mins so -so. over 10 mins = go back to school and stand in the corner
2. 20 Sep '03 22:22
Originally posted by skeeter
Ok , this is an oldie but a goodie

You have eight identical looking balls but one of them is heavier than the others in this set. Using ONLY a set of balance scales and with ONLY two weighings how does one discover which ball is the heaviest in the set. under 1 minute = einstein. 1 - 5 mins = brilliant . 5 - 10 mins so -so. over 10 mins = go back to school and stand in the corner

All right, where's my coat ? ðŸ™‚

3. skeeter
515 + 30 days
20 Sep '03 22:41
hmmmmm.. maybe but I see you are creaming group six in the long haul tourney. Still waters run deeper me thinks....hmmmmm
4. 20 Sep '03 23:13
pick them up with ur hands and try an work out the heavier that way?
5. skeeter
515 + 30 days
20 Sep '03 23:20
close, but no cigar. I think I mentioned you need to use the scales to solve this one
6. 20 Sep '03 23:24
weigh it by hand then to make sure pick up the ball that u think it is and weigh it against any other (as they will all be the same) then if wrong try again by hand then repeat to make sure that u use the scales twice
7. skeeter
515 + 30 days
20 Sep '03 23:32
lets see now - I'm sure the original post said &quot; using ONLY a set of balance scales....&quot; Better get YOUR coat too and stand in the corner with Ivanhoe ðŸ˜µ
8. 21 Sep '03 00:55
Originally posted by skeeter
lets see now - I'm sure the original post said " using ONLY a set of balance scales...." Better get YOUR coat too and stand in the corner with Ivanhoe ðŸ˜µ

Lóóóóóóóól ðŸ˜µ
9. 21 Sep '03 01:04
Originally posted by skeeter
hmmmmm.. maybe but I see you are creaming group six in the long haul tourney. Still waters run deeper me thinks....hmmmmm

As I remember correctly you're also in the same group six
and not giving in yet. I can assure you I'm after your scalp too ! ðŸ˜µ

However I believe you'll be a very tough nut to crack !

10. skeeter
515 + 30 days
21 Sep '03 02:17
I've got both my hands full just dealing with Crusoe so you are on the back burner at the moment. But I also see you took a game off him and it appears even in the other.ðŸ˜ž Catch you on the back nine Ivanhoe and do you have a solution to the 8 balls problem??

BR's the skeeter
11. 21 Sep '03 10:01
Originally posted by skeeter
I've got both my hands full just dealing with Crusoe so you are on the back burner at the moment. But I also see you took a game off him and it appears even in the other.ðŸ˜ž Catch you on the back nine Ivanhoe and do you have a solution to the 8 balls problem??

BR's the skeeter

If my memory serves me well there has been a similar problem in some thread in the &lt;Posers and Puzzles&gt; forum not so long ago.
At the moment I'm too lazy to put any energy into solving the problem (again) ... I'm sorry ðŸ˜ž Shame on me. I'd better get my coat again huh ... ðŸ˜³
The weekend isn't over yet and I guess there will be (new) RHP members who will love to have a go at this one, because it is a very nice problem with an elegant solution.
I must be on my way ... got some scalps to hunt.

By the way, between the two of us. What does that mean: &quot;Catch you on the back nine&quot;. Psssst, you see, I'm Dutch and I'm afraid It's not in my dictionary. Can you help me out here, pléééééase. Don't tell anybody ðŸ˜³

12. 21 Sep '03 10:17
eh...if i understand the question right...i could do it with 9 balls too. Put three balls on each scale. When the left scale is heavier, you know the heavy one is one of the three balls on the left, when the right scale is heavier you know it is on the right, when they are equal you know it is one of the three balls you didn't put on a scale. you then take the group of three balls where the heavy one is in and put one of them one the left scale and one on the right. You now know which ball it is...
13. 21 Sep '03 11:40
Originally posted by Nuathala
eh...if i understand the question right...i could do it with 9 balls too.
Yes with 9 balls you can do it too. But for the human mind (not for the computer) it is more confusing when you mention eight balls.
You can expand the question for 3 weighs and 27 balls. But if you put it that way the solution is to obvious. You can make it more difficult when you mention 3 weighings and 25 balls.

Fjord
14. 21 Sep '03 16:01
but what if on the second weighing you put the heavier ball with a lighter ball compared to just one lighter ball-therefore the second reading is an inadequate measure of testing
15. skeeter
515 + 30 days
22 Sep '03 04:33
Nuathala and Fjord are abso correct and it sounds more complex if you state 8 balls instead of nine.

On a lighter note I rang God yesterday, as it's only a local call for us Kiwi's, and asked him what was wrong with Mr Tanker.

Oh him , God said. Nothing too much except that when I created him I did ask him what type of BRAIN he wanted and he must have thought that I had said TRAIN, because he asked for a slow one !!

another gem from the skeeter