[pdurrant]

Originally Posted by Javed

Think I got it!

Spoiler:

Pour from the 16 pint container into the 7 pint container until full.

Pour from that 7 pint container into the 3 pint container until the 3pint container is fulll.

Discard what is in the 3.

Pour the remainder of the 7 pint container which is 4 pints back into the 16pint container.

Pour from the 16pint container into the 7 pint container until full.

Pour from the 7 pint container into the 3 pint container until full.

Discard what is in the 3.

Pour the remainder of the 7 pint container into the 16 pint container.

The 16 pint container now has 8 pints (one gallon).

Sorry, not right. You have a couple of errors.
The first is assuming that the 16 pint bucket is full. It isn't. It's only nearly full.
The second is discarding water from the wrong container — you'd end up with 10 pints.

I can see what you're trying to do, but even if you'd discarded the right container, it still doesn't work, because you don't start off with 16 pints.

Try again!