a- is the first job of the project o and n are the two final jobs for project completion k- precedes o n- follows l and

[answerhappygod]

a- is the first job of the project o and n are the two final
jobs for project completion k- precedes o n- follows l and m j-
restricts the start of k and m c and b depends on the completion of
a d follows b and may go on in parallel with c and e e follows c
t-restricts the start of j and l h and galso restrict k and m f
must precede g and may go in parallel with h e and d restrict h and
i c- must precede f.