A courier must deliver four distinct parcels (A, B, C, and D) across a grid, but strict routing protocols apply. Parcel A must be delivered before B. Parcel C cannot be delivered until D has reached its destination. If B is delivered before C, what is the absolute last parcel that can possibly be delivered?
Parcel C
Since A must precede B, and B precedes C, the chain of dependencies is A -> B -> C. Additionally, D must precede C. Therefore, C depends on both B and D having been delivered, making C the final parcel in the sequence.
About this riddle
Logic riddles give you a few facts and ask what must be true. List what you know, cross out what cannot be, and see what is left.
Difficulty: Medium. More like this: Logic riddles with answers or try Einstein's Logic Grid for a different kind of puzzle.
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