Following are activities, precedence relationships, and task times for a number of tasks.

Task Task Time $($days$)$ Preceding Task

A $5$ None

B $2$ A

C $4$ A

D $5$ B

E $6$ C

F $7$ D

G $4$ E

H $5$ D

I $1$ C

J $4$ I, F

K $3$ G$,$ J

L $7$ H$,$ K

M $4$ L

a$.$ Construct a precedence diagram.

b$.$ Compute early and late times.

c$.$ Compute the slack for each task.