Answer
a) $100$
b) $\frac{1}{4}$
Work Step by Step
a) In the first step, there are 5 servers. In the second step there are also 5 servers. Finally, in the third step, there are 4 servers.
The total number of paths is $5 \times 5 \times 4 = 100$
b) Since what happens in the first and second step does not affect the outcome of the third step, the probability that the 1st of the 4 servers is chosen is $\frac{1}{4}$ because there are 4 servers, and each server has an equal chance of being selected.
