Transmission of information between computers s and t (see figure) is possible if there is at least one closed path between s and t. The figure indicates the possible interruption of an edge...

Transmission of information between computers s and t (see figure) is possible if there is at least one closed path between s and t. The figure indicates the possible interruption of an edge (connection between two nodes of the transmission graph) by a switch. In practice, such an interruption may be caused by a cable break or if the transmission capacity of a channel is exceeded. All 5 switches operate independently. Each one is closed with probability p and open with probability 1 - p. Only switch 3 allows for transmitting information into both directions.

(1) What is the probability that w_s, t(p) s can send information to t?

(2) Draw the graph of w_s, t(p) as a function of p, 0 ≤ p ≤ 1.