Let X be the discrete r.v. that represents the number of Tails when tossing a fair coin for three times. What is the expected value of this discrete probability distribution? [ Select ] ["1", "0.5",...

Let X be the discrete r.v. that represents the number of Tails when tossing a fair coin for three times.

What is the expected value of this discrete probability distribution?                             [ Select ]                          ["1", "0.5", "1.5", "2"]

What is the variance?                             [ Select ]                          ["0.75", "0.6", "0.867", "0.25"]