Jill has 4 pints of water in a 4-pint bucket. Jack has an empty 1-pint bucket and an empty 3-pint bucket. None of the buckets has measurement markings. How can they divide the water so each has exactly 2 pints?
Fill the 3-pint bucket from the 4-pint bucket. Fill the 1-pint bucket from the 3-pint bucket, leaving you 2 pints. Pour the 1-pint contents into the 4-pint bucket.
To divide the water so each person has exactly 2 pints, Jill should pour 2 pints of water from her 4-pint bucket into Jack's empty 3-pint bucket. This leaves Jill with 2 pints of water remaining in her 4-pint bucket.
Next, Jack should pour the 3 pints of water from his 3-pint bucket into his empty 1-pint bucket. This will fill up the 1-pint bucket completely, leaving Jack with 2 pints of water remaining in his 3-pint bucket.
Now, Jack has 2 pints of water in his 1-pint bucket, and Jill has 2 pints of water in her 4-pint bucket. They have divided the water equally, with each person having 2 pints.