The activity table is given below
Activity Predecessor Duration ES LF
0-1 Clear site 3 0 3
1-2 Survey and layout 2 3 5
2-3 Rough grade 2 5 7
3-4 Drill wel 15 7 22
3-6 Water tank foundations 4 7 12
3-9 Excavate sewer 10 7 21
3-10 Excavate electrical manholes 1 7 21
3-12 Pole line 6 7 29
4-5 Well pump 2 22 24
a. Draw the CPM network with path duration and determine the critical path
b. Draw the CPM path with ES, EF.LS,LF and determine the critical path