Please Show work:

$(1)$ Given the network shown, what is the earliest start time for activity F$?$

A$.6$

B$.8$

C$.10$

D$.13$

E$.16$

$(2)$ Given the network shown, what is the latest finish time for activity B$?$

A$.5$

B$.8$

C$.10$

D$.11$

E$.13$

$(3)$ Given the network shown, what is the slack time for activity D$?$

A$.1$

B$.2$

C$.3$

D$.4$

E$.5$