1) Two refills for a ballpoint pen are selected at random from a box that contains 3 blue refills, 2 red refills, and 3 green refills. If is the number of blue refills and is the number of red refills selected

find (1,2), (1.5,2), and (5,7).

2)Suppose that a radioactive particle is randomly located in a square with sides of unit length. That is, if two regions of equal area are considered, the particle is equally likely to be in either region. Let and denote the coordinates of the particle's location. The joint probability distribution is

, = 1, 0 1, 0 1 0 here

(a) Sketch the probability density surface.

(b) Find (0.2, 0.4).

(c) Find (0.1 0.3, 0 0.5).