if you have Mathematica; 25 if you must write your own code.] Suppose Peter Piper of Puerile Publications, Example 6.3.3, discovers that he must add 10 more workstations to their system (business is booming at Puerile). Use his model to do the following:
(a) Calculate $\lambda$ and $W$ for the current system with 10 more workstations, that is, $N=40$.
(b) Calculate $\lambda$ and $W$ with $N=40$ for an upgraded file server that has $D_1=0.1, D_2=0.4$, and $D_3=0.2$ (all values in seconds).
(c) Calculate $\lambda$ and $W$ with $N=40$ for an upgraded file server consisting of the original CPU but a single $I / O$ device, that is much faster because of caching and a faster disk drive so that $D_1=0.3$ seconds and $D_2=0.02$ seconds.