Analytical Puzzles
Hard
2 min
Five tasks A, B, C, D and E must be completed in order subject to these rules: A before C, B before D, C before E, and D before E. Which task must be completed last?
Hint
E depends on both C and D.
Answer
E.
Explanation
E must occur after C and D. Since A must precede C and B must precede D, E necessarily comes after every other task.
Step-by-Step Solution
A → C → E.
B → D → E.
Therefore E must be last.
B → D → E.
Therefore E must be last.