A 6L jug, an 11L jug, a tap, and no markings on either. Measure exactly 7L. There is a way, it takes eight steps, and no amount of staring at the numbers will hand it to you — you have to search.
This sheet asks for the sequence rather than the count, and that is deliberate. The fewest steps is always 4, 6 or 8 — so a child who writes a number alone has a one-in-three chance of being right without pouring anything. The question names the three kinds of step, so the count is unambiguous, and the ruled line under each is where the sequence itself goes: fill, pour, empty, pour, in order.
Why this sheet works
"Fewest" is a promise the sheet can keep. Each route is found by searching outward from two empty jugs one step at a time, so the first route that reaches the target is provably the shortest — there is no shorter one to miss. The answer key prints that route in full, which means a child who found a seven-pour solution can see exactly which pour was wasted.
A step = fill a jug, empty a jug, or pour one into the other. Show the order.
1You have an 11L jug, a 24L jug, and a tap. Neither jug has any markings.What is the fewest steps that leave exactly 22L in a jug?Steps
2You have a 3L jug, an 18L jug, and a tap. Neither jug has any markings.What is the fewest steps that leave exactly 6L in a jug?Steps
3You have a 7L jug, a 12L jug, and a tap. Neither jug has any markings.What is the fewest steps that leave exactly 3L in a jug?Steps
Jug puzzles · Jugs to 25LAnswer key
1. fill the 11L jug → pour the 11L jug into the 24L jug → fill the 11L jug → pour the 11L jug into the 24L jug — the 22L is now in the 24L jug. That is 4 steps.2. fill the 3L jug → pour the 3L jug into the 18L jug → fill the 3L jug → pour the 3L jug into the 18L jug — the 6L is now in the 18L jug. That is 4 steps.3. fill the 12L jug → pour the 12L jug into the 7L jug → empty the 7L jug → pour the 12L jug into the 7L jug → fill the 12L jug → pour the 12L jug into the 7L jug → empty the 7L jug → pour the 12L jug into the 7L jug — the 3L is now in the 12L jug. That is 8 steps.
