First, fill up the 3 gallon jug to the top, and pour it into the 5 gallon jug. 5 - 3 = 2 free gallons left in the 5 gallon jug. Now, fill up the 3 gallon jug again, and pour as much as you can into the 5 gallon jug. 3 - 2 = 1 gallon of water left in the 3 gallon jug. Finally, pour the remaining gallon of water from the 3 gallon jug into your 1 gallon jug. Result = 1 gallon of water! Copyright 2003 magicofmath.org