In probability, assume I have a set of n labeled balls [1..n]. I pick two balls randomly and uniformly without returning them.
Assume I have two random variables X and Y such as: X represents the selection of the first ball and Y represents the selection of the second ball.
now, I know that the expectancy of Y (E[y])) is (N+1)/2, however I cannot seem to prove it. Using the law of total expectation how can I show this?