Go to Post Saying that something cannot be done, is always good inspiration for someone to find a way to do it. - Josh Hambright [more]
Home
Go Back   Chief Delphi > Other > Math and Science
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Reply
Thread Tools Rate Thread Display Modes
  #1   Spotlight this post!  
Unread 18-10-2005, 11:00
Denman's Avatar
Denman Denman is offline
Tie Wrap-Not Cable Tie or Zip tie
AKA: Stephen Denman
FRC #0759 (Systemetric)
Team Role: Mentor
 
Join Date: Jan 2004
Rookie Year: 2003
Location: Cambridge UK
Posts: 817
Denman has much to be proud ofDenman has much to be proud ofDenman has much to be proud ofDenman has much to be proud ofDenman has much to be proud ofDenman has much to be proud ofDenman has much to be proud ofDenman has much to be proud ofDenman has much to be proud of
Send a message via ICQ to Denman Send a message via AIM to Denman Send a message via MSN to Denman Send a message via Yahoo to Denman
coins in a dark room

There is a room
In the room are 50 coins
18 of them are showing tails
The rest are showing heads.

In the dark without being able to tell which way up the coins are
Sort then in to two groups
With the same amount of heads showing in each group.

answers on a post
__________________
I am an ex-member of team 759.
759: regional winners with 522 and 233 NYC (2004)


FIRSTWiki.org - Contribute, learn, inspire.

"Teach the way of the GP and the way of the GP shall teach you" - Me
Reply With Quote
  #2   Spotlight this post!  
Unread 18-10-2005, 12:15
KenWittlief KenWittlief is offline
.
no team
Team Role: Engineer
 
Join Date: Mar 2003
Location: Rochester, NY
Posts: 4,213
KenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond repute
Re: coins in a dark room

I think you grab 25 coins and flip over 7 of them

have to work this out
Reply With Quote
  #3   Spotlight this post!  
Unread 18-10-2005, 12:20
RogerR's Avatar
RogerR RogerR is offline
its spelled *ya'll*, not *y'all*
AKA: Roger Riquelme
FRC #3844 (Wildbots)
Team Role: Teacher
 
Join Date: Feb 2003
Rookie Year: 2001
Location: Somerset, KY
Posts: 913
RogerR has a reputation beyond reputeRogerR has a reputation beyond reputeRogerR has a reputation beyond reputeRogerR has a reputation beyond reputeRogerR has a reputation beyond reputeRogerR has a reputation beyond reputeRogerR has a reputation beyond reputeRogerR has a reputation beyond reputeRogerR has a reputation beyond reputeRogerR has a reputation beyond reputeRogerR has a reputation beyond repute
Send a message via AIM to RogerR Send a message via MSN to RogerR
Re: coins in a dark room

Quote:
Originally Posted by KenWittlief
I think you grab 25 coins and flip over 7 of them

have to work this out
actually, i think it might be the other way around; grab 25, and flip 18.

i outta be studying for a fluid mech. exam, but this riddle keeps distracting me...
__________________
"But to say that the race is a metaphor for life is to miss the point. The race is everything. It obliterates whatever isn't racing. Life is a metaphor for the race." -- Donald Antrim
Reply With Quote
  #4   Spotlight this post!  
Unread 18-10-2005, 12:35
KenWittlief KenWittlief is offline
.
no team
Team Role: Engineer
 
Join Date: Mar 2003
Location: Rochester, NY
Posts: 4,213
KenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond repute
Re: coins in a dark room

{Ken starts warming up his vintage Cray 1}
Reply With Quote
  #5   Spotlight this post!  
Unread 18-10-2005, 12:38
MikeDubreuil's Avatar
MikeDubreuil MikeDubreuil is offline
Carpe diem
FRC #0125 (Nu-Trons)
Team Role: Engineer
 
Join Date: Jan 2003
Rookie Year: 1999
Location: Boston, MA
Posts: 967
MikeDubreuil has a reputation beyond reputeMikeDubreuil has a reputation beyond reputeMikeDubreuil has a reputation beyond reputeMikeDubreuil has a reputation beyond reputeMikeDubreuil has a reputation beyond reputeMikeDubreuil has a reputation beyond reputeMikeDubreuil has a reputation beyond reputeMikeDubreuil has a reputation beyond reputeMikeDubreuil has a reputation beyond reputeMikeDubreuil has a reputation beyond reputeMikeDubreuil has a reputation beyond repute
Send a message via AIM to MikeDubreuil
Re: coins in a dark room

Choose a common coin type, let's say you feel US dimes. Put the dimes in one group and the rest of the coins in a different group. Bingo, 2 groups of coins
EDIT: Oops, forgot about the heads up part.
__________________
"FIRST is like bling bling for the brain." - Woodie Flowers
Reply With Quote
  #6   Spotlight this post!  
Unread 18-10-2005, 12:41
Jack Jones Jack Jones is offline
Retired
no team
 
Join Date: Jan 2003
Rookie Year: 2003
Location: Waterford, MI
Posts: 964
Jack Jones has a reputation beyond reputeJack Jones has a reputation beyond reputeJack Jones has a reputation beyond reputeJack Jones has a reputation beyond reputeJack Jones has a reputation beyond reputeJack Jones has a reputation beyond reputeJack Jones has a reputation beyond reputeJack Jones has a reputation beyond reputeJack Jones has a reputation beyond reputeJack Jones has a reputation beyond reputeJack Jones has a reputation beyond repute
Re: coins in a dark room

Stand them on edge.
Reply With Quote
  #7   Spotlight this post!  
Unread 18-10-2005, 12:47
KenWittlief KenWittlief is offline
.
no team
Team Role: Engineer
 
Join Date: Mar 2003
Location: Rochester, NY
Posts: 4,213
KenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond repute
Re: coins in a dark room

Jack has left the box :^)

some coins wont stand on their edge

how bout, put 25 in your left pocket, and 25 in your right pocket?

(no heads are showing in either pocket)
Reply With Quote
  #8   Spotlight this post!  
Unread 18-10-2005, 12:55
Jack Jones Jack Jones is offline
Retired
no team
 
Join Date: Jan 2003
Rookie Year: 2003
Location: Waterford, MI
Posts: 964
Jack Jones has a reputation beyond reputeJack Jones has a reputation beyond reputeJack Jones has a reputation beyond reputeJack Jones has a reputation beyond reputeJack Jones has a reputation beyond reputeJack Jones has a reputation beyond reputeJack Jones has a reputation beyond reputeJack Jones has a reputation beyond reputeJack Jones has a reputation beyond reputeJack Jones has a reputation beyond reputeJack Jones has a reputation beyond repute
Re: coins in a dark room

Ken took the money and ran^

The room is dark -> group anyway you want - neither group has any heads showing : zero == zero
Reply With Quote
  #9   Spotlight this post!  
Unread 18-10-2005, 13:00
KenWittlief KenWittlief is offline
.
no team
Team Role: Engineer
 
Join Date: Mar 2003
Location: Rochester, NY
Posts: 4,213
KenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond repute
Re: coins in a dark room

as you pick up each coin, cut it in half

put the two halfs in separate piles

or better yet, you get an elephant, a bowling ball, and 4 pounds of wax...
Reply With Quote
  #10   Spotlight this post!  
Unread 18-10-2005, 15:15
Denman's Avatar
Denman Denman is offline
Tie Wrap-Not Cable Tie or Zip tie
AKA: Stephen Denman
FRC #0759 (Systemetric)
Team Role: Mentor
 
Join Date: Jan 2004
Rookie Year: 2003
Location: Cambridge UK
Posts: 817
Denman has much to be proud ofDenman has much to be proud ofDenman has much to be proud ofDenman has much to be proud ofDenman has much to be proud ofDenman has much to be proud ofDenman has much to be proud ofDenman has much to be proud ofDenman has much to be proud of
Send a message via ICQ to Denman Send a message via AIM to Denman Send a message via MSN to Denman Send a message via Yahoo to Denman
Re: coins in a dark room

Quote:
Originally Posted by KenWittlief
or better yet, you get an elephant, a bowling ball, and 4 pounds of wax...
lol
i don't know the answer either
its bothering me
__________________
I am an ex-member of team 759.
759: regional winners with 522 and 233 NYC (2004)


FIRSTWiki.org - Contribute, learn, inspire.

"Teach the way of the GP and the way of the GP shall teach you" - Me
Reply With Quote
  #11   Spotlight this post!  
Unread 18-10-2005, 15:21
KenWittlief KenWittlief is offline
.
no team
Team Role: Engineer
 
Join Date: Mar 2003
Location: Rochester, NY
Posts: 4,213
KenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond repute
Re: coins in a dark room

Quote:
get an elephant, a bowling ball, and 4 pounds of wax...
the rest is intuitively obvious
this is my standard answer for all brainstorming sessions, no matter what the question or problem is
Reply With Quote
  #12   Spotlight this post!  
Unread 18-10-2005, 15:25
brandy836's Avatar
brandy836 brandy836 is offline
billy talent supports 836
AKA: Brandy Reed
FRC #0836 (Robobees)
Team Role: Alumni
 
Join Date: Mar 2005
Rookie Year: 2004
Location: California, MD
Posts: 257
brandy836 is a splendid one to beholdbrandy836 is a splendid one to beholdbrandy836 is a splendid one to beholdbrandy836 is a splendid one to beholdbrandy836 is a splendid one to beholdbrandy836 is a splendid one to behold
Re: coins in a dark room

Why don't you just turn on the light, and then flip over the coins?
__________________
-Brandy
836
The Robobees

Reply With Quote
  #13   Spotlight this post!  
Unread 18-10-2005, 15:37
Denman's Avatar
Denman Denman is offline
Tie Wrap-Not Cable Tie or Zip tie
AKA: Stephen Denman
FRC #0759 (Systemetric)
Team Role: Mentor
 
Join Date: Jan 2004
Rookie Year: 2003
Location: Cambridge UK
Posts: 817
Denman has much to be proud ofDenman has much to be proud ofDenman has much to be proud ofDenman has much to be proud ofDenman has much to be proud ofDenman has much to be proud ofDenman has much to be proud ofDenman has much to be proud ofDenman has much to be proud of
Send a message via ICQ to Denman Send a message via AIM to Denman Send a message via MSN to Denman Send a message via Yahoo to Denman
Re: coins in a dark room

Quote:
Originally Posted by brandy836
Why don't you just turn on the light, and then flip over the coins?
because it defeats the object of the excercise
lol
__________________
I am an ex-member of team 759.
759: regional winners with 522 and 233 NYC (2004)


FIRSTWiki.org - Contribute, learn, inspire.

"Teach the way of the GP and the way of the GP shall teach you" - Me
Reply With Quote
  #14   Spotlight this post!  
Unread 18-10-2005, 15:39
brandy836's Avatar
brandy836 brandy836 is offline
billy talent supports 836
AKA: Brandy Reed
FRC #0836 (Robobees)
Team Role: Alumni
 
Join Date: Mar 2005
Rookie Year: 2004
Location: California, MD
Posts: 257
brandy836 is a splendid one to beholdbrandy836 is a splendid one to beholdbrandy836 is a splendid one to beholdbrandy836 is a splendid one to beholdbrandy836 is a splendid one to beholdbrandy836 is a splendid one to behold
Re: coins in a dark room

I knew that, but then Ken said something about some elephant so I thought I was entitled to say something about the lights.

Was this a homework assignment or something?
__________________
-Brandy
836
The Robobees

Reply With Quote
  #15   Spotlight this post!  
Unread 18-10-2005, 15:49
KenWittlief KenWittlief is offline
.
no team
Team Role: Engineer
 
Join Date: Mar 2003
Location: Rochester, NY
Posts: 4,213
KenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond reputeKenWittlief has a reputation beyond repute
Re: coins in a dark room

I think I reasoned it out, I had the right idea on my first post, but the wrong number

the original pile has 32 heads up, so you take 32 from the pile and flip them over. That is your second pile.

If you grabbed all 32 heads then there are no heads left in either pile

if you grabbed 18 heads and 18 tales, then you left 18 heads in the first pile, and when you flip the second pile you have 18 heads in both piles

if you grabbed 19 heads and 17 tales, then you left 17 heads in the first pile, and when you flip the second you have 17 heads and 19 tails

it works for all combinations

but I like the pocket answer better :^)

Last edited by KenWittlief : 18-10-2005 at 21:08.
Reply With Quote
Reply


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Harmony Dark Sky Festival -Join us! Barry Bonzack General Forum 2 08-02-2008 12:46
Share a room at the OMNI anyone? Rob Colatutto Off-Season Events 7 15-07-2003 13:00
Why Ashlee is the new owner of the tigerbolt chat room. Joe Ross General Forum 23 03-11-2002 16:50
a request for chat room archiver 2001 4 24-06-2002 01:15
Check your Disney room charges! Mike Martus Championship Event 3 15-04-2002 22:06


All times are GMT -5. The time now is 12:15.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi