# If you have a 3 litre bottle, and a 5 litre bottle, how can you measure out 4 litres using only those two bottles?

### 10 Answers

- PuzzlingLv 71 month agoFavourite answer
Assuming we don't have any other containers:

Method 1:

Step 1 - Fill the 3 and pour it into the 5 --> 0, 3

Step 2 - Fill the 3 again and pour what you can into the 5 --> 1, 5

Step 3 - Empty the 5 and transfer the 1 into it --> 0, 1

Step 4 - Fill the 3 one more time. The total is 4 --> 3, 1

(Optional) Step 5 - If you need them in one container, pour the 3 into the 5 --> 0, 4

Method 2:

Step 1 - Fill the 5 and pour what you can into the 3 --> 2, 3

Step 2 - Empty the 3 and transfer the 2 into it --> 0, 2

Step 3 - Fill the 5 and pour what you can (1) into the 3 --> 4, 3

(Optional) Step 4 - Empty the 3 so you only have 4 liters --> 4, 0

- KrishnamurthyLv 73 weeks ago
If you have a 3 liter bottle, and a 5 liter bottle,

how can you measure out 4 liters using only those two bottles?

Fill the 3-liter bottle and pour it into the empty 5-liter bottle.

Fill the 3-liter bottle again, and pour enough to fill 5-liter bottle. This leaves exactly 1 liter in the 3-liter bottle.

Empty the 5-liter bottle; pour the remaining 1 liter from the 3-liter bottle into the 5-liter bottle.

Fill the 3-liter bottle and pour it into the 5-liter bottle. The 5-liter bottle now has exactly 4 liters.

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- PinkgreenLv 71 month ago
assume that the 2 bottles are just different in height only.

(1) Fill up the 5-L bottle with water.

(2) Fill up the 3-L bottle with water from the 5-L bottle, what

remains in the latter is 2 Ls.

(3) Pour off some water from the 3-L bottle until it contains

the same level of water as that in the 5-L bottle.

(4) Add all water to the 5-L bottle from the 3-L bottle. Now

what in the 5-L bottle is exactly 4 Ls of water.

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- PhilomelLv 71 month ago
Fill the 3.

dump it into the 5.

fill the 3.

dump it into 5.

dump the 5.

pour the 3 into the 5.(1L)

fill the 3.

dump 3 into the 5. (4L)

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- sepiaLv 71 month ago
If those are truly my only containers.

Fill 5 litre bottle.

Use 5 litre bottle to fill 3 litre bottle ( leaves 2 litres in 5 litre bottle)

Empty 3 litre bottle.

Place the remaining 2 litres from the 5 litre bottle into the 3 litre bottle. (5 litre empty, 3 litre has 2 litres)

Fill the 5 litre bottle. 5 + 2 litres

Use the 5 litre. Bottle to fill the 3 litre bottle the rest of the way. At this step the 5 litre bottle has 4 litres in it and the 3 litre bottle is full. 4 + 3

If necessary to appease the math genie asking you this question, empty the 3 litre bottle. 4 + 0.

No other container needed.

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- skeptikLv 71 month ago
1: Fill the 5-liter bottle.

2: Pour that into the empty 3-liter bottle. Two liters are left in the first bottle.

3: Dump that two liters into a container.

Repeat steps 1: - 3:

You now have 4 liters in your other container.

---------

If you don't have to just measure with the 3 and 5 liter bottles, but can't use any other containers, you can still do it, but it's a little more complicated.

1: Fill the 3-liter bottle.

2: Pour that into the empty 5-liter bottle.

3: Refill the 3-liter bottle.

4: Pour as much as you can into the partially-filled 5-liter bottle.

You now have one liter in the 3-liter bottle, and five in the 5-liter bottle.

5: Empty the 5-liter bottle.

6: Pour the one liter from the 3-liter bottle into the empty 5-liter bottle.

7: Refill the (now-empty) 3-liter bottle.

You now have one liter in the 5-liter bottle, and three in the 3-liter bottle.

8: Pour all of it into the 5-liter bottle.

There are now 4 liters in the 5-liter bottle. Success.

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- VamanLv 71 month ago
What you need an empty vessel. Fill 3 lt pour it in5 lt. There will be a space or 2 lt. Fill 3 liter put it in 5 lt. You will be left with 1 lt. Pour that in 5 liters after emptying it. Then pour 3 liters again. Now you have 4 lts. You need a third vessel.

what if you pour the 3 into the 5, then fill the 3 and pour that into the 5 until it is full, now leaving you with 1 in the 3, empty the 5 and pour the 1 in the 5, fill the 3 and pour into the 5 for 4 litres, no need for a 3rd vessel

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- Master ShakeLv 41 month ago
Fill 5 dump into 3, leaves you with 2 in the 5. Then just repeat for 4

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- David B.Lv 71 month ago
If you have another container that will hold the 4 liters you can by filling the five-liter bottle and then pouring three liters into the other bottle. the remaining liquid is 2 liters. empty that into a vessel and repeat. You will have 4 liters as a result.

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- 1 month ago
both bottles full will give you 8 litres in total...

So half both bottles

- ...Show all comments
I think, you have the electronic eyes.

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You could pour the liquid back into the original source location if you're worried about wasting it. In any case, I believe this is the intended answer to this contrived problem.