Question 3 (20 points): A person tosses three dice at once. He wins if there are at least two
six appearing. This person plays 5 times.
a. Find the probability that the person wins at least 2 times.
b. How does the answer in (a) change if after each tossing, the previous numbers
cannot appear anymore. For example: if 1 appears in the first toss, there are only 5
outcomes in the second toss (two to six with equal chances), and so on.
c (**) (extra 5 points). Imagine you want to cheat and can increase the chance of the
number 6 to your desire. Compute the minimum chance of the number 6 to make sure
the probability in (a) increases to 50%.