Weighing a Counterfeit Coin,
a selection of answers from the Dr. Math archives.
 Find the Heavier Coin of 12
in 3 Weighings
 If there are twelve coins in a bag, one of which is either lighter
or heavier than the others, find the fake coin in exactly 3 weighings
AND determine if it is lighter or heavier than the others.
 Finding the Counterfeit Coin
(1 of 9)
 One of nine coins is counterfeit and is lighter or heavier than the
others. How do I locate it in three weighings only?
 Finding One Coin of 12 in
3 Steps
 Given a pile of twelve coins of equal size with one of a different
weight, in three weighings find the unequal coin...
 3 Weighings Problem
 You have a balance scale and 12 balls that all look and weigh the
same except one...
 Use One Weighing
 There are 90 genuine coins and 10 fake coins in 10 stacks with
10 coins in each stack... Using only one weighing, determine which
stack contains the fake coins.
