You have 2 ball of each A,B,C colors and each color have 1 light and 1 heavy ball. All light balls are of same weight same goes for heavy. Find out weight type of each ball in minimum chances. You can use a two sided balance system (not the electronic one).
This puzzle was asked in many interviews – Drishti-soft, Yahoo, Infoedge.
Simply, you can check by taking 2 balls of same color. Now, comparing those balls with other balls but this will take 3 chances for each color type ball.
Answer is 2 chances.
So, Make a table for all conditions for all 6 balls that will help in understanding and solving this problem.
First weight A1,B1 and B2,C1 -> 3 cases equal ,left is heavy or left is light.
Equal, if equal weight simply B1,B2 will solve the problem.
If A1+B1 > B2+C1, then we know B1 > B2. Also just that A1>=C1.
Next compare A1,B1 and A2,C1
If A1+B1 = A2+C1 means A2 is heavy and A1=C1 light
If A1+B1 > A2+C1 means A2 is light and A1=C1 heavy
A1+B1 < A2+C1 will not happen because B1 is any way heavier.
If A1+B1 > B2+C1
Similar to above case we can check it.