vinudh

• Oct 7th, 2005

 

Ans x=36

vikrant

• Dec 7th, 2005

 

Ans : x=2take division as 3,3,3take any 3,3 if both are equal then remining 3 coins have the fake coinotherwise the higher weight side contain the fake cointhis is one weight requirednow divide 3 coin as 1,1 ,1 and this require only one weight to determine the fake coin

kripal

• Sep 4th, 2006

 

vikrant's answer is right & more appropriate

But there is one more possibility

Divide coins into 4 & 4 & keep in right & left pans of the balance 

keep the remaining 1 coin in hand

If the coins weighs equal, then the coin in your hand is the fake one

Here x=1.

But the probability of this method to be successful is 1/9

Sagar Wani

• Mar 2nd, 2007

 

Take 9 coins as a 3,3,3. take 2,3,3 then weighed it if both are equal balance then other 3 is a fake coin. but if the weight of other coin is more then it is fake coin. and another is take 3 as 1,1,1 weighed it & it gives a fake coin. so in this way there are two ways. ans:-2

aishwarya .k

• Mar 20th, 2007

 

Hi Friends .
First as others mentioned before weigh 8 coins equally on the two pans of balance. if they
are equal the fake one is in our hand. else take the 4 coins which weigh high. Go for second trial by balancing
equal. definitely one pan will weigh more. Now take those two coins and weigh again to find the fake one.
its like a series 4 4 leave 1coin
of the four high weighing coins take 2 2 of two high weighing pan take as 1 1
you get the fake coin so min=1, max=3 weighing
ash @ sastra

dexter7574

 Profile Answers by dexter7574 

• May 18th, 2007

 

Its 2,

divide it as 3,3,3....then weigh two of the 3's ..if same the remaing 3 weigh 1-1...if heavy take the heavy 3 and weigh 1-1...

Gampeshwar Sahu

• Nov 26th, 2007

 

ans is 2-- we can take it as 3-3-3 and could continue till two steps to find out the fake coin

prabu.thil

 Profile Answers by prabu.thil 

• Jul 14th, 2009

 

Rest one coin first
Split the remaining 8 coins into two parts (four coins)
If they are weighted both sides are equal, then the rested is the fake coin
If not equal in the 2 parts, took the low weight part and split into 2 (2,2 coins) and took the less weight part and split the part into 2 part by(1,1 coins) and find the fake within the 3 times of balance
So the value of x ranging from 1 to 3

praneeta

 Profile Answers by praneeta 

• Oct 15th, 2010

 

First you take the 2 coins one on each pan, these 2 coins must be taken such that the pans are balanced.
Then by keeping one of them undisturbed, now replacing the other coin with the remainig 7 coins, we can get the fake coin as the pans wont be in balanced position when fake coin is kept.