A bag contains 4 balls. Each ball is a single color, and 3 distinct colors are represented in the bag. What is the probability that the first 2 balls selected without replacement are the same color? Express your answer as a common fraction.
Let's say... 1 red, 1 green, 2 blue.
The new question is... What is the probability of selecting 2 blue balls?
First chance... 1 blue ball has chance 2/4, or 1/2.
Second chance... 1 blue ball has chance 1/3. This is because 1 blue ball is left... and only 3 balls are left.
Multiply these two chances... 1/6 probability.