Plan from the supplied facts
Fictional prerequisite graph is A→C, B→C, C→D. An arrow requires its source before its destination. A and B can appear in either order; C must follow both. The worksheet checks ordering only, with no durations or staff assumptions.
| Proposed order | Valid | Edge check |
|---|---|---|
| A,B,C,D | Yes | All three forward |
| B,A,C,D | Yes | All three forward |
| A,C,B,D | No | B→C reversed |
Work through the choice
For every edge, compare the two positions. A plausible-looking order can still violate one less-visible prerequisite.
Does B,A,D,C satisfy the graph?
Show the worked answer
No. C→D requires C before D, but D appears first. A and B being ready does not remove C’s prerequisite.
Material to use in your plan
Use an edge table with prerequisite, dependent, proposed positions and pass/fail. Reject duplicate or omitted nodes separately before evaluating every edge.