An environmental engineer suspects mercury contamination in an area which contains three lakes and two streams. He will check all five for mercury contamination.

a) Express each outcome using two coordinates, so (2,1), for example, represents the event that twp of the lakes and one of the strems will be contaminated. Draw a diagram similar to that of Figure 3.1 showing the 12 outcomes in the sample space.

b)If R is the event that equally many lakes and strems are contaminated, T is the event that none of the streams is contaminated, and U is the event that fewer lakes than streams are contaminated, express each of these events symbolically by listing its elements.