There are 3 mislabeled jars with Black and White balls in the first and the second jar respectively. The third jar contains a mixture of white and black balls. Now, you can pick as many balls as required to label each jar correctly. Tell the minimum number of balls to be picked up in this process of labeling the jars.

If you notice the condition in the question, you will observe that there is a circular misplacement. By which I mean that, if Black is wrongly labeled as Black, Black cannot be labeled as White. So, it must be named as Back + White. If you consider that all the 3 jars are wrongly placed, that is, Black + White jar contains either the Black balls or the White balls, but not the both. Now, just assume you pick one ball from the Black + White jar and let us assume it to be a Black ball. So, obviously, you will name the jar as Black. However, the jar labeled Black cannot have Black + White. Thus, the third jar left in the process should be labeled Black + White. So, if you just pick up one ball, you can correctly label the jars.