You have nine pearls, one of which is (as is usually the case in these problems) fake. You know that the fake pearl weighs less than the others, but it is (of course) impossible to distinguish from the others in any other way.
What is the minimum number of weighings that must be performed to find the fake pearl? How would you go about it?
2. take 3 verses three, then if one group goes down, one vs one, and whichever is lighter is the fake coin, or if they= each other, then that one is it. if at the first weighing the scale balances out, then you do the same thing with the third group. if you do not know if the coin is heavier or lighter, then it is immpossible to do it in two weighings, but possible in three.
of course
