One Robot, One Hour
Understand the puzzle
The exact puzzle
A robot does one task at a time. It always finishes a task before starting another — it never stops partway. Whenever the robot is free, it starts the SHORTEST task that has already arrived and is still waiting. Three tasks arrive: Task 1 needs 3 hours and arrives at 9:00 am. Task 2 needs 4 hours and arrives at 10:00 am. Task 3 needs 2 hours and arrives at 12:00 noon. Which task finishes LAST, and at what time?
Why this matters
Prototype by hand-simulating a rule before trusting it
Take your time reading. There's no rush at all. Use the picture on the side to help it make sense, then tell me what it's really asking.