There are 6 white balls and 4 red balls in an urn. Consider selecting one ball at a time from the urn. What is the probability that the first ball is...

There are 6 white balls and 4 red balls in an urn. Consider selecting one ball at a time from the urn. What is the probability that the first ball is white and the second ball is also white? Express the probability in fraction format. (Show all work.)

(a) Assuming the ball selection is with replacement.

(b) Assuming the ball selection is without replacement.