If only the Climate Crisis were this easy.
At least its attempting to bring some awareness to the issue.
There are two ways to do the water jugs.
The other way, that they use in the movie...
Fill the 5 gallon jug. Pour 3 gallons from the 5 gallon jug into the 3 gallon jug, leaving 2 gallons in the 5 gallon jug. Pour out the 3 gallon jug. Pour the 2 gallons from the 5 gallon jug into the 3 gallon jug. This leaves the 5 gallon jug empty, and 2 gallons in the 3 gallon jug. Refill the 5 gallon jug, fill the last one gallon to the 3 gallon jug leaving 4 gallons in the 5 gallon jug.
The real issue here is the jugs are clearly not full and they spill a bit, which would not be a problem except Simon said not to be off by even an ounce. I suppose it may have been hyperbole, or just BS.