Logical Puzzles
Hard
2 min
Four tasks W, X, Y and Z must be completed one at a time. W must be before X. Y must be before Z. X must be before Y. Which task must be completed third?
Hint
Combine the dependency chains.
Answer
Y.
Explanation
The dependencies require W before X before Y before Z, so Y must be third.
Step-by-Step Solution
W < X.
Y < Z.
X < Y.
Therefore W < X < Y < Z.
Y is third.
Y < Z.
X < Y.
Therefore W < X < Y < Z.
Y is third.