I know this will seem stupidly simple once someone explains, but my brain has been struggling for a minute and I was obviously impressed by this because it’s a screenshot of an advert that’s been sitting on my phone since forever.
- Fill the 3L jug.
- Pour the 3L jug into the 5L jug. The 5L jug now has exactly 3L of water.
- Fill the 3L jug again.
- Pour the 3L jug into the 5L jug until it is full. There is now 5L of water in the 5L jug, and 1L remaining in the 3L jug.
- Pour out the 5L jug.
- Pour the 1L of water from the 3L jug into the 5L jug.
- Fill the 3L jug and pour it into the 5L jug. There is now exactly 4L of water in the 5L jug.
And they say die hard didn’t teach us anything.
Thank you very much!
Might as well add my own solution:
- Fill the 5L jug
- Pour the 5L jug into the 3L jug until the 3L jug is full
- Now the 5L jug contains 2L
- Empty the 3L jug
- Pour the 5L jug into the 3L jug
- Now the 3L jug contains 2L
- Fill the 5L jug
- Pour the 5L jug into the 3L jug until the 3L jug is full
- Now the 5L jug contains 4L
Ah wait, this solution was already posted. Should’ve read all the comments first!
Haha, I just found this clip on YouTube. Thank you
- Fill 5l
- Use 5l to fill 3l
- Ditch 3l
- Your 5l now contains 2l
- Move 2l from 5l to 3l
- You now have 0l and 2l
- Fill 5l again full and fill 3l to the top Now you have 4l in 5l and 3l in 3l
Overall whoever sets this task should be shot as you just wasted a crap ton of water instead of using a measuring jug…
wasted a crap ton of water
You drew 10 𝑙 to obtain 4 𝑙. Out of that, 3 𝑙 can still be recovered from the small can. Not great, not terrible.
Doesn’t really matter when your life is on the line.
Thank you!
If the 4L can be poured somewhere else, it gets even easier:
- fill 5L can
- pour from 5L into 3L. 5L now has 2L left. Pour that somewhere.
- repeat above once more to add another 2L.
Thank you!
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Full the 5L jug, then pour it into to 3L jug. Now there’s 2L in the 5L container, and the 3L jug is full.
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Dump out the 3L jug and pour the 2L into it. Now the 5L jug is empty.
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Fill the 5L jug again, then pour into the 3L jug until it’s full. There’s only room for 1L, so that leaves 4L in the bigger jug. Dump out the small jug, é voila!
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This was what I thought of. The other way seems overly complicated.
