You have a 5 gallon jug and a 3 gallon jug. You have no other measuring devices.

Measure out exactly 4 gallons of water (Assume you have a river handy, or some other limitless water supply).

Fill the 5 gallon jug.

Then fill the 3 gallon jug from 5 gallon jug. There will be two gallons left in the 5 gallon jug.

Empty the 3 gallon jug, and pour the two gallons fron the 5 gallon jug into it.

Fill the five gallon jug.

Fill the 3 gallon jug from the 5 gallon jug. Since there are already two gallons of water in it, it will only take one gallon more, leaving four gallons in the 5 gallon jug.

Posted by TomM on 2002-11-02 08:16:05