Puzzle - You are given 12 identical appearing marbles, out of which one is defective. You are given a balance of old type i.e a small dish hangs from each end of a rod which is balanced in the middle. So you can conclude if both sides are equal or unequal where heavier side will be lower compared to lighter side. Find the defective marble in three weighings.
Here is the tree diagram for above mentioned problem. It shows how we can find out the defective marble along with its weight - lighter or heavier in three weighing. L here represents lighter, and H represents Heavier.