Content

• To step
• Method 1 of 2: Finding the answer (hints)
• Method 2 of 2: The solution to the puzzle
• Solution 1
• Solution 2

You have to defuse a bomb by placing exactly 4 liters of water on a sensor. The problem is that you only have a 5 liter jar and a 3 liter jar! Made famous by the movie Die Hard 3, this classic riddle may seem impossible without a measuring cup, but it is essentially very simple.

To step

Method 1 of 2: Finding the answer (hints)

1. Simplify the question and your options. Don't think about the movie for a moment, but about the riddle in its simplest terms. What do you know, what is your goal and what are your options? An easier way to look at the riddle goes like this: You have two empty water jugs in your hands. One holds 3 liters of water and the other holds 5 liters of water. You have to use these two jugs to measure exactly 4 liters of water. You have an unlimited amount of water to use.
2. Determine in which jug you will store the 4 liters of water. To be able to measure your 4 liters of water, you have to put it in something. As John McClane rightly concludes, it cannot fit in the 3 liter jug, so the correct amount of water will have to be in the 5 liter jug.
3. Know that like any good riddle, you have everything you need to solve it. The solution does not involve bringing in another jug, or perfectly sized water levels, or determining jug sections. You have two jugs and an unlimited amount of water. How can you use these two things to get 4 liters? In other words, how can you use 3 and 5 to make 4?
   • Unlimited amount of water means you can use or throw away as much as you want.
   • You cannot guess exactly how much water there is in a jug unless you fill it all the way to the brim.
4. Realize that this is essentially a simple arithmetic problem. If you get stuck, ignore the water and the jugs for a moment.How can you add and subtract 3's and 5's to get 4? This is really all you have to do; the numbers just happen to represent liters. Adding or throwing away water is no more than addition and subtraction.

Method 2 of 2: The solution to the puzzle

Solution 1

1. Fill the 5 liter completely. There is of course 5 liters of water in the 5-liter jug. You have to fill the jug all the way to the top, otherwise you will not be sure how much you have.
2. Use the water from the 5-jug to fill the 3-jug. You have 3 liters of water in the 3-jug and 2 liters in the 5-jug.
3. Empty the 3-jug. There is now no more water in the 3-jug and 2 liters in the 5-jug.
4. Pour the water from the 5-liter jug ​​into the three-liter jug. There is now 2 liters in the 3-jug. There is nothing more in that of 5-liter.
5. Fill the 5-jug to the brim. You now have 2 liters in the 3-liter jug ​​and 5 in the 5-liter jug. This means that there is still 1 liter of space in the 3-jug.
6. Use the water from the 5-jug to fill the 3-jug. Fill the last liter of space in the 3-jug with water from the 5-jug. This leaves you 3 liters in the 3-liter jug, and 4 liters in the 5-jug.

Solution 2

1. Fill the 3-jug to the brim with water. You now have 3 liters of water.
2. Pour this water into the 5-jug. There is now nothing left in the 3-jug, and 3 liters in the 5-jug.
3. Refill the 3-jug with water. You now have 3 liters of water in the 3-jug and 3 liters in the 5-jug.
4. Fill the 5-jug with water from the 3-jug. You now have 1 liter of water left in the 3-jug and 5 liters in the 5-jug. This is because you only had 2 liters of space left in the last step, so you could not transfer more than 2 liters.
5. Empty the 5-jug and refill it with 1 liter from the 3-jug. There is now nothing left in the 3-jug and 1 liter in the 5-jug.
6. Fill the 3-jug to the brim with water. You now have 3 liters of water in the 3-jug and 1 in the 5-jug.
7. Pour the 3 liters of water into the 5-jug so that you get 4 liters of water. Now simply pour the 3 liters into the 5-liter jug, which only contained 1 liter. 1 + 3 = 4 and you have successfully defused the bomb.