Problem 71 Answer
Weigh any three pearls against any other three. If one side
is higher than the other the fake pearl is on that side. If the
sides stay equal the fake pearl is in the three you didn't use.
For the second weighing take any two of the bad three and
weigh one against the other. If one side goes up that side
has the fake pearl. If the two sides stay the same the unused
pearl of the three is fake.
Michael Shackleford, A.S.A.