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## In 80 coins one coin is counterfiet what is minimum number of weighings to find out counterfiet coin?

This question is related to TCS Interview## Editorial / Best Answer

Himanshu AshwaniProfile Answers by Himanshu Ashwani Questions by Himanshu Ashwani

The answer is 4

Divide Coins As 27 27 26

now weigh 27 and 27 keeping on both sides of pan u will get the less one

and if both sides are equal then group that has 26 coins has the coin that is counterfiet...

if u get 27 as result divide it in 3 groups

9 9 9

and weight it

keep two groups on two sides of pans and get the result of both sides are equal then the group 9 which was not kept on the pan has the coin which is counterfiet....

now 9 is divided as in 3 groups as

3 3 3 and weigh again and get result

now divide 3 as

1 1 1 and get the coin..

in start if u get answer as 26 divide as 3 groups

9 9 8

wiegh by keeping 9 on both sides and get answer if both are equal then 8 is ans

if 9 is ans again divide as 3 3 3 and then 1 1 1 and get coin...

if u get 8 then divide as 2 2 2 then 1 1 less one be yours coin...

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