COINS

United States
September 20, 2006 6:02am CST
You are given 9 coins that looks exactly the same. 8 of them are made in gold and 1 is false. The false coin is lighter then the others. By using a letter scale, how many tries is the least you need to find the false coin?
4 responses
shi_2000_21
@shi_2000_21 (2680)
• India
18 Oct 06
in 3 attempts i could take out the false coin.
prasad1961
@prasad1961 (5597)
• India
18 Oct 06
one attempt is enough. Place 4 coins each on either side, balance it. That's all. The one left is the false.
hotmale
@hotmale (810)
• Pakistan
17 Oct 06
well u said so the false coin is lighter........
remyalmc
@remyalmc (42)
• India
30 Sep 06
within 7 tries we can get it....7 is the max number of trials....