There are 4 red balls, 6 blue balls and 2 white balls in a bag. Suppose on every single turn, you randomly select a ball, see the color of it and put it back in the bag. You keep doing this...

There are 4 red balls, 6 blue balls and 2 white balls in a bag. Suppose on every single turn, you
randomly select a ball, see the color of it and put it back in the bag. You keep doing this
repeatedly.
a. What is the probability that you get the first red ball on the 5th turn?
b. How many turns are expected to get one non-white ball?
c. What is the variance of the number of turns required to get one blue ball?