24 replies to this topic

[rookie1ja]

Pouring water VI. - Back to the Water and Weighing Puzzles
Given three bowls: bowl A (8 liters capacity) filled with 5 liters of water; bowl B (5 liters capacity) filled with 3 liters of water; and bowl C (3 liters capacity) filled with 2 liters of water.
Can you measure exactly 1 liter, by transferring the water only 2 times?

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Spoiler for Solution

Pouring Water VI. - solution
1st Pour 1 litre from bowl A to bowl C. Thus 4 litres are left in the bowl A and bowl C is full (3 litres).
2nd Pour 2 litres from bowl C to bowl B. Doing that you have full bowl B (5 litres) and there is 1 litre left in bowl C.

[jmo]

this reminded me of the Die Hard With a Vengeance puzzle in the park, so I kept asking myself how can you be so sure that you're only pouring one liter? It made me through a bunch of solutions out the window. Good solution though.

[mrbojangles]

got it

[Duff]

1. top off bowl C with water from bowl A
2. top off bowl B with water from now full bowl C. What's left is in bowl C is 1L of water.

[wayne11]

Doesn't this solution go against the principles in all the other water jug problems?
The first step in the solution says to

Pour 1 litre from jug A into jug C.

How do you know how much 1 litre is?? And, if you could pour single litres out of jugs, why not just pour 1 litre out of the 3-litre jug and be finished in 1 step? Am i wrong?

[wayne11]

I just realized I was wrong indeed...

[bigbic]

How do you know how much 1 litre is?? And, if you could pour single litres out of jugs, why not just pour 1 litre out of the 3-litre jug and be finished in 1 step? Am i wrong?

because being as C only has one liter of empty space in it, so long as you fill it up you are taking ONE liter away from what ever pitcher you used to pour into it. Same thing for the second step, pur 2 liters into B. B only has 2 liters of empty space in it so to filll it up you are taking 2 liters aways from C. C had three before this step, 3 - the 2 liters going into B and there you have it. 1 liter left in C

[harrylemmens]

Alternatively you can use the following solution:
1. Fill C with B leaving 4 litres in B
2. Fill A with B leaving 1 litre in B.

Can't get easier than that


Oh BTW deplacing 1 litre implies that you can only fill the container with a max of 1 litre. There's no measuring involved here.

[bonanova]

Alternatively you can use the following solution:
1. Fill C with B leaving 4 litres in B

B starts with 3 liters.
Filling C [takes 1 liter] leaves 2 [not 4] liters in B.

[irakmae3]

You don't need B at all.
Fill C from A leaving 4 liters in A.
Dump out the water in C.
Then fill C from A again, leaving 1 Liter in A