There are 9 coins. 8 are of 1 gm and 1 is of 2 grams. How will you find out the heavier coin in minimum number of weighing and how many weighing it will need?

• divide 9 coins into three groups...(a group of three)
  select any two group and weigh them
  if they are equal then the odd coin is in the other group . if the weights are not equal select the heavier grou and divide into three .
  select any two and weigh them ..if they are equal the odd coin is the other one which is outside the weighing pan . or select the heavier one from pan.
  thus a total of "two" iteration are needed.
• 15 years agoHelpfull: Yes(64) No(3)
• 2 weighing ( Divide the number of coins into 3 parts at each weighing)
• 12 years agoHelpfull: Yes(6) No(3)
• 2 weighing
• 10 years agoHelpfull: Yes(1) No(1)
• 2times. Take group of 3 and 3 coins and weigh if it is equal then rest have a odd one.
• 9 years agoHelpfull: Yes(0) No(0)
• YOU CAN FIND OUT THE ANSWER IN "1 or 3 Steps" in the following way:
  1.divide the 9 coins into 2 groups each of this consist of 4 coins and 1 coin is remaining.
  calculate the weight of the group if the 2 are equal then remaining coin is heavier.
  2. otherwise, any one of the group weight is heavier then divide the group into 2 parts each of which consists of 2 coins , calculate the weight of the group one the part is heavier.
  3. after that divide the group into 2 parts each which is 1 coin and then calculate the weight. one the coin is heavier then that is the answer.
• 9 years agoHelpfull: Yes(0) No(0)
• 2 weighing only
  9coins====>3 groups
• 9 years agoHelpfull: Yes(0) No(0)
• minimum no. of weighing need =3
• 8 years agoHelpfull: Yes(0) No(1)
• total 9 coins divided into 3 coins in each pair. the number of pairs are 3
  weight first two pairs. if there is no equal weight then take third one
  take one coin from third pair on one side and another coin on another side foe weighing
• 6 years agoHelpfull: Yes(0) No(0)