can you measure this?

You could fill the 3 gallon container with mud and dump it in the 5 gallon container and then let it harden, so you'd have room for only 2 gallons, and then fill it up twice.

Or, dump 10 gallons of water(two five gallons) into a container and take out 6.(two three gallons)

God, you have only the two jars, so no to both answers

Well, that makes no sense. What are you going to do with the water?

Fill the 5er and then use it to fill the 3. You will have 2 gallons left in the 5.

Empty the 3 and then put the 2 gallons from the 5 into the 3. Then fill the five and pour from it into the three till the 3 is full and you'll ahve 4 in the jug.

Was this riddle in Die Hard 3? I remember something similar in a fountain.

Thats it Craven,

Dont know about Die Hard 3 havn't seen it.