History Main / ThreePlusFiveMakeFour

** The original version also appears in "SherlockHolmesAndTheMysteryOfTheMummy" as well as "SherlockHolmesAndTheMysteryOfThePersianCarpet" (Which borrowed every other puzzle too)

** The original version also appears in "SherlockHolmesAndTheMysteryofTheMummy" as well as "SherlockHolmesAndTheMysteryofthePersianCarpet" (Which borrowed every other puzzle too)

It bears noting that this puzzle, like many other stock puzzles, is usually difficult only because the solver is overthinking it. In practice, if you actually have the two jugs, and you just start filling one jug and pouring it into the other, the solution presents itself very quickly. (This is incorporated in some tellings of the riddle, which demand that you come up with the answer in less than a minute, as an Aesop about the value of trying things out rather than just sitting there thinking.)

* This puzzle and several variants appear in the ''ProfessorLayton'' series.

* ''PerplexCity'' used this one on a card.

* Done with [[spoiler: lava]] in the last chapter of the Wii ''CarmenSandiego'' game.

* This puzzle appears pretty much verbatim in ''[[VideoGame/DrBrain The Castle of Dr. Brain]]'', where you essentially had to solve nothing ''but'' different types of [[StockPuzzle puzzles]] from all across the spectrum in order to progress through the titular castle.

* ''{{VideoGame/TombRaiderTheLastRevelation}}'' has a level with three scales, each needing a different amount of water.

* This puzzle appears in ''KnightsOfTheOldRepublic'' on Manaan, and solving it is a prerequisite for the "good" ending on that planet.

* This puzzle appears pretty much verbatim in ''The Castle of Dr. Brain'', an old MS-DOS game where you essentially had to solve nothing ''but'' different types of [[StockPuzzle puzzles]] from all across the spectrum in order to progress through the titular castle.
* A variation of this puzzle occurs in ''FatalHearts'', where you need ⅔ cup of flour but have only an 800ml cup and a 100ml cup. The puzzle's not too hard if you're good at conversions.

* Appears in ''{{Runescape}}'', among other {{Stock Puzzle}}s.

* Appears in ''Phantasmat'' as an unusual method of switching on a generator.

* An apparently more complex version of this classic puzzle appears at the end of ''SherlockHolmesVersusArseneLupin'', where you have to measure exactly 478cc of black powder with only 250cc, 80cc and 12cc containers at your disposal. I say apparently only, because [[spoiler:1×250 + 19×12=478, so you don't actually have to use the pour-bigger-into-smaller subtraction trick at all to solve it]].

* Done with [[spoiler: lava]] in the last chapter of the Wii "CarmenSandiego" game.

* In the movie ''DieHardWithAVengeance,'' the two main characters must solve this type of puzzle in order to disarm a bomb near a public fountain.\\

[[WhatCouldHaveBeen In the original script]], the bomb was a ChekhovsGun, as the movie would end with [=McClane=] planting the bomb on the bad guy's helicopter, and upon discovering one of them [[GallowsHumor asks]] [[BrickJoke if anyone has a four gallon jug]] (in the final script the bomb was used for something else entirely without the puzzle being brought up again).

* In the movie ''DieHardWithAVengeance,'' the two main characters must solve this type of puzzle in order to disarm a bomb near a public fountain.

* A slight variant with different values in ''VideoGame/{{Zork}} Zero'', a game almost entirely composed of [[StockPuzzle stock puzzles]].

* In the movie ''DieHard with a Vengeance,'' the two main characters must solve this type of puzzle in order to disarm a bomb near a public fountain.

* A slight variant with different values in ''{{Zork}} Zero'', a game almost entirely composed of [[StockPuzzle stock puzzles]].

Maths nerd bit: You're looking for the smallest ''x'' and ''y'' that satisfy 3''x''−5''y''=4; then fill the 3-liter ''x'' times, pouring it into the 5-liter when full, and emptying the 5-liter when it's full (which you'll do ''y'' times). The solution is ''x''=3 and ''y''=1. The alternate solution up there is the dual formulation, 5''x''−3''y''=4 (''x''=2, ''y''=2). From here, two details present themselves: one, that it's easily adaptable to other values other than 3 and 5, and two, that a solution exists only if the target value is either a factor or a multiple of the highest common factor of the container sizes (e.g. you can't get 4 liters from 6- and 3-liter containers).

** [[spoiler:It ''can'' be done much faster with the pour-bigger-into-smaller trick, though: 1x250 + 3x80 − 1x12=478.]]

It bears noting that this puzzle, like many other stock puzzles, is usually difficult only because the person is overthinking it. In practice, if you actually have the two jugs, and you just start filling one jug and pouring it into the other, the solution presents itself very quickly. (This is incorporated in some tellings of the riddle, which demand that you come up with the answer in less than a minute, as an Aesop about the value of trying things out rather than just sitting there thinking.)

Maths nerd bit: You're looking for the smallest ''x'' and ''y'' that satisfy 3''x''-5''y''=4; then fill the 3-liter ''x'' times, pouring it into the 5-liter when full, and emptying the 5-liter when it's full (which you'll do ''y'' times). The solution is ''x''=3 and ''y''=1. The alternate solution up there is the dual formulation, 5''x''-3''y''=4 (''x''=2, ''y''=2). From here, two details present themselves: one, that it's easily adaptable to other values other than 3 and 5, and two, that a solution exists only if the target value is either a factor or a multiple of the highest common factor of the container sizes (e.g. you can't get 4 liters from 6- and 3-liter containers).

* A slight variant with different values in ''Zork Zero,' a game almost entirely composed of [[StockPuzzle stock puzzles]].
* This puzzle appears pretty much verbatim in ''The Castle of Dr. Brain'', an old MS-DOS game where you essentially had to solve nothing BUT different types of [[StockPuzzle puzzles]] from all across the spectrum in order to progress through the titular castle.
* A variation of this puzzle occurs in ''FatalHearts'', where you need 2/3 cup of flour but have only an 800ml cup and a 100ml cup. The puzzle's not too hard if you're good at conversions.

** [[spoiler:It ''can'' be done much faster with the pour-bigger-into-smaller trick, though: 1x250 + 3x80 - 1x12=478.]]

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<<|StockPuzzle|>>

* This puzzle and several variants appear in the DS game ''ProfessorLayton and the Curious Village''.

#Empty out the 5-liter container, then pour the 1 liter of water into it from the 4-liter container.

#Empty out the 5-liter container, then pour the 1 liter of water into it from the 3-liter container.