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One of the classical puzzles is pouring water into the 5 gallon jug so there is 4 gallons of water remaining. This was popularized by Bruce Willis in "Die Hard with a Vengeance". I was wondering however, if there was a possible way to complete the puzzle using a 3 gallon jug and a 7 gallon jug to still get the 4 gallons.
If so, what other combinations of jugs could you use to still get the same four gallon requirement?
Edit: When doing the 4 gallons remaining from the 7 gallon jug, you must have 1 gallon of water left in the three gallon jug.