For each problem, determine $\backslash$lambda $,\backslash$mu $,$ and S$.$

$1.$ Customers come with questions or complaints or matters regarding credit$-$card bills. The customers are served by $3$ store representatives, each located in a partitioned stall. Customers are treated on a first$-$come, first$-$served basis. A study of the service department for $6$ months shows that an average inter$-$arrival time is $6$ minutes and an average of $4$ customers can be served per hour by a customer service representative

Activity Immediate

Predecessor Normal

Time Crash

Time Normal

Cost Crash

Cost

A $----53$ $ $1000$ $ $1120$

B A $52$ $ $2500$ $ $2590$

C A $42$ $ $2000$ $ $2040$

D A $21$ $ $5000$ $$5040$

E B$,$C$,$D $31$ $ $3000$ $$3100$

F E $21$ $ $4000$ $ $4100$

$1.$ What is the project completion time before it crashes? $(2$ points$)$

$2.$ Which activity should crash first to reduce the completion time to one day? $(3$ points$)$

$3.$ Suppose you crashed one day. If you want to crash another day after crashing one day,

which activity $($or activities$)$ should you crash? day, which activity $($or activities$)$ should

you crash? $(4$ points$)$

$4.$ What is $($a$)$ the project completion time of the fully crashed project and $($b$)$ the total

additional cost of the fully crashed project? $(6$ points$)$