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?

You can't. The 1 pint bucket will not hold 2 pints.

Also, there are 3 buckets. 3x2=6.

The question is horribly flawed.

From the 4L can, fill the 1L can

Condidtion:
4L can : has 3 L
1L can is full
3L can is emptyl

pour the remaining 3L from the 4L can into the empty 3 L can
Condition:
4L can is empty
1L can is full
3L can is full

Pour the 1L can back into the now empty 4L can, and fill the 1L from the 3L can
Conditon:
4L can holds 1 L
1L can has 1 L
3L can has 2 L

pour the 1L can into the 4L can

Final condition
4L can has 2 L
1L can is empty
3L can has 2 L

so Jill has 2 L in her 4L can, and Jack has 2 L in his 3L can.

But then the 1 liter bucket has 0 liters of water.

I interpreted the "they" in "How can they divide the water so each has exactly 2 pints?" as referring to Jack and Jill.

Jack and Jill were the subjects in the first two sentences.

Badly written question, then, right? The word "each" needs to be clarified.

I agree.

To divide the water so that each person has exactly 2 pints, Jill and Jack can follow these steps:

1. First, Jill should pour 2 pints of water from her 4-pint bucket into Jack's empty 3-pint bucket.
- Now, Jill has 2 pints of water left in her 4-pint bucket, and Jack's 3-pint bucket has 2 pints of water.

2. Next, Jack should pour the 2 pints of water from his 3-pint bucket into his empty 1-pint bucket.
- After this step, Jack's 3-pint bucket will be empty, and his 1-pint bucket will have 2 pints of water.

3. Finally, Jill should pour the remaining 2 pints of water from her 4-pint bucket into Jack's 1-pint bucket.
- Now, Jill's 4-pint bucket will be empty, and Jack's 1-pint bucket will also have 2 pints of water.

At this point, both Jill and Jack will have exactly 2 pints of water.