Puzzle No. 023
Picarats: 40


Here we have an eight-quart pitcher filled with juice, an empty five-quart pitcher, and an empty three-quart pitcher.

The pitchers are unmarked, and your task is to divide the eight quarts of juice so that both the five-quart pitcher and the eight-quart pitcher are each holding exactly four quarts.














Hint One: This puzzle can be frustrating because it's easy to end up back where you started.

Pay special attention to difference, particularly the one-quart difference between five quarts and four quarts.

Hint Two: If you pour the contents of the five-quart pitcher into the three-quart pitcher, you are left with two quarts.

If you're aiming to isolate four quarts, you just need to remove one quart from five. To get that one quart, you just need to create a single quart's worth of space in another pitcher.

Hint Three: If you pour the contents of the five-quart pitcher into the three-quart pitcher, you are left with two quarts. Next, empty the three-quart pitcher and pour in the two quarts you had stored in the five-quart pitcher.

Well, look at that! How many quarts worth of space do you have left in that three-quart pitcher now?

Solution:

 

If you keep at it long enough, you're sure to come across the solution. The shortest possible solution requires seven moves. These liquid distribution problems have been around for ages, and have even been spotted in Japanese texts from hundreds of years ago.