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Topic: coins problem
Replies: 7   Last Post: Jun 16, 2009 10:34 PM

 Messages: [ Previous | Next ]
 Brendan Posts: 3 Registered: 12/4/04
Solution!!
Posted: Jan 27, 1999 7:15 PM

Dear Helena,

I read your problem and have solved it straight away!
The key to the problem is being able to reduce the original number of
coins to 3...for obvious reasons.

I must warn you...I'm only fourteen so I may not be able to answer
what you really wanted.

However, I think one can determine the odd coin from 24 coins in four
weighings.

Weighing 1 = determine heavier 12coins
2 = determine heavier 6coins
3 = determine heavier 3 coins
4 = determine heaviest coin

One cannot determine the odd coin from 38 in 4 weighings. This is
because by the end of the third weighing one is left with four coins.
In a single weighing one cannot find one heavier coin.

I hope you find this useful.

Brendan

Date Subject Author
1/27/99 Helena Verrill
1/27/99 Sarah Seastone
1/27/99 Brendan
1/27/99 John Conway
1/28/99 John Conway
2/1/99 Helena Verrill
2/1/99 John Conway
6/16/09 Barco You