If you have to measure exactly 4 liters of water but you only have a 3-liter bottle and a 5-liter bottle How do you do it?

Answer 1

As illustrated in the 1995 movie Die Hard 3 (Bruce Willis, Samuel K. Jackson), you can measure out exactly 7 liters in the following manner:

1. Fill the 5 liter container, then use that 5 liters to fill the 3 liter container.
2. Dump out the 3 liter container.
3. What was left in the 5 gallon container is 2 liters. Pour this into the 3 liter container.
4. Fill the 5 liter container again.
5. You now have 7 liters : 5 in the large container and 2 in the smaller one.

Answer 2

Empty the 3 liter container into a spare container or containers. Fill the 3 liter container from the 5 liter container - This leaves 2 liters in the 5 liter container. Empty the 3 liter container into the spare container(s). Pour the 2 liters of water from the 5 liter container into the 3 liter container. Fill the 5 liter container from your spare container(s). Now you have a full 5 liters plus the 2 liters in the 3 liter container = 7 liters. Or, you can combine both volumes and take out one liter.

Answer 3

So say you want 4 litres in a basin. Fill up the 5 litres, then fill up the 3 litres from the 5 litres. You are left with 2 litres in the 5l jug. pour that into the basin. Empty the 3l jug down the sink and repeat everything again to get a second 2 litres and pour this into the basin to get 4 litres

Answer 4

Fill the 3oz container and pour the contents into the 5oz container.

There is now 3oz in the 5oz container.

Fill the 3oz container and fill the 5oz container with the contents of the 3oz container.

The 5oz container is now full, and the 3oz container holds 1oz.

Empty the 5oz container and pour the contents of the 3oz container into the 5oz container.

There is now 1oz in the 5oz container.

Fill the 3oz container and pour the contents into the 5oz container.

There is now 4oz in the 5oz container.

Answer 5

2) Fill the 3 again. Pour 2 into the 5. 1 remains in the 3.

3) Empty the 5. Pour the 1 from the 3 into the 5.

4) Fill the 3 again. Pour it into the 5 that already has 1 in it. Voila!

Answer 6

First of all, you'd need something else to put the water into, other than the two cups. Then you would need to fill the 5L cup all the way full with water. After that, you would pour exactly enough water from the 5L cup into the 3L cup so that the 3L cup is full. After it's full, you could dump all the water out of the 3L cup. Then you would need something else to hold the water, so that you could dump the water in the 5L cup into it, which at that point would measure 2L. Then you repeat the process, and the something else holding the water would have exactly 4L of water in it.