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).

(In reply to easy solution by Mary Fisher)

That would work if you also had a large, but unspecified "bucket" to dump the 2 gallons into, but if all you have are the two jugs, when you dump the "first" 2 gallons, you lose them, just like when you emptied the 3 gallon jug.

Posted by TomM on 2002-11-03 13:06:05