There are 6561 cricket balls out of them 1 is heavy. Find the minimum no. of times the cricket balls have to be weighed for finding out the heavy ball.
A. 8 B. 5 C.7 D.9

• 6561 if u notice is 3^8...n can be divided by 3(prime factor) only...we keep on dividing it into sets of 3 and in 1 weighing itself you can determine which set is heavy. Divide that set into further 3 lots...keep doing that..
  6561
  2187 2187 2187 1st weighing
  729 729 729
  243 243 243
  81 81 81
  27 27 27
  9 9 9
  3 3 3
  1 1 1
  ANswer is 8 attempts
  
• 10 years agoHelpfull: Yes(40) No(0)
• sir ,
  a lot of solution is there out of them which is correct.
• 10 years agoHelpfull: Yes(3) No(1)
• 6561 if u notice is 3^8...n can be divided by 3(prime factor) only...we keep on dividing it into sets of 3 and in 1 weighing itself you can determine which set is heavy. Divide that set into further 3 lots...keep doing that..
  6561
  2187 2187 2187 1st weighing
  729 729 729
  243 243 243
  81 81 81
  27 27 27
  9 9 9
  3 3 3
  1 1 1
  ANswer is 8 attempts
  
• 10 years agoHelpfull: Yes(2) No(2)
• divide in 3 groups 6561/3=2187...we need only 1 comparison in 3 groups to find the heaviest group.
  and now again divide this heavey group of 2187 into 3 pices...i.e 2187/3=729..similarly here also u need 1 comparision
  .
  .
  .so now dividing again and again by 3...there ther will be total 7 comparision...in last comparision there will remain only 3 balls.
  
  ANS=7
• 10 years agoHelpfull: Yes(1) No(4)
• ans: 8.
  (3^8 = 6561 )
• 10 years agoHelpfull: Yes(1) No(1)
• ans is 9 as 6561 is only divisible by 9
  
• 10 years agoHelpfull: Yes(1) No(2)
• 6561=3^8
  ans. 8
• 10 years agoHelpfull: Yes(1) No(1)
• answer is definitely 9 in such kinda ques always find 3^n and then answer is n+1 as for 1 3^0 also be used
• 10 years agoHelpfull: Yes(1) No(2)
• Answer is 5
  6561 can also be divided in 9 groups of 729. weighing the 9 groups will give us the heaviest group. again divide 729 in 9 groups of 81 each and so on.
  6561
  729
  81
  9
  1
  thus it is 5 times.
• 10 years agoHelpfull: Yes(1) No(2)
• if 3^3=9 devide 3 3 3 wait one time
  then 1 1 1,second time so besicaly total power -1,, h
  here 3^8.
  ans 8-1=7
• 10 years agoHelpfull: Yes(0) No(2)
• the answer is 9,because the weight of all the balls is not known,so we will have to check the weight of the whole set first and then carry on ,diving by 3.
• 10 years agoHelpfull: Yes(0) No(2)
• out of this many answers which one right,please give one exact answer
• 10 years agoHelpfull: Yes(0) No(0)
• this question is from gate paper..........answer will be 2
• 10 years agoHelpfull: Yes(0) No(3)
• i cant get the solution.plz any1 can explain it.
• 10 years agoHelpfull: Yes(0) No(2)
• eww .. i could n find , which one is correct 7 or 8 ?
• 10 years agoHelpfull: Yes(0) No(2)
• @SOMI... is it always to divide with least prime number.??? we can divide 6561 by 3 as well as 9. If 3 No doubt ans is 8 but 9 then ans is 5 .So please explain ur ans ... !!
• 10 years agoHelpfull: Yes(0) No(1)
• 8
  is the ans
• 10 years agoHelpfull: Yes(0) No(0)
• 8 is the correct answer
• 10 years agoHelpfull: Yes(0) No(0)