1.A pair of fair dice are cast, and the number of rolled dots, on each die, is recorded. Let X denote the minimum of the two numbers. Find the probability mass function of X.

2.Answer the following questions. Which distribution best describes the following?

(A) The number of times we need toflip a fair coin before we get

Head for the first time.

(a)Hypergeometric(100, 50, 10). (b) Geometric (0.5). (c) Poisson (50).

(d)Binomial (100, 0.5). (e) none of the above

(B) The number of numbers which are smaller or equal to 10 when we select 5 numbers from among 1,...,100 without replacement.

(a) Hypergeometric (10,5,100). (b) Hypergeometric ( 5,50, 100).

(c) Geo-metric(0.1). (d) Poisson(0.5). (e) Binomial(5, 0.1).