Brain Builder

 Brain Builder:  

A mason has two empty containers, one a three gallon and the other a five gallon. How can he measure exactly one gallon of water for his mix, without wasting any water?

Answer:

Fill the three gallon container up and dump it into the five gallon container. Fill the three gallon container up again and pour the water in the five gallon container until the five gallon container is full. This leaves one gallon in the three gallon container.

Thanks for playing.