The Water Jug Challenge : Puzzle

You've got a 4 liter jug and a 9 liter jug. 

You've got a pool of water. 

What is the fewest number of steps it takes to come up with exactly 6 liters of water? 

No, you cannot pour some water into the 9 liter jug and then guess. Nor can you fill each jug up half way or something. You have to be exact. A step is defined as putting water into a jug (not emptying). For instance, filling the 4 liter jug and then pouring it into the 9 liter jug is 2 steps.

Click here for SOLUTION! 

The Water Jug Challenge Puzzle : Solution

What was the puzzle?

We've got a 4 liter jug and a 9 liter jug. 

We've got a pool of water. 

We have to find fewest number of steps it takes to come up with exactly 6 liters of water. 

STEPS : 

1. Fill up the 9 liter jug from the pool.         9L - 9  4L - 0

2. Fill up the 4 liter jug from the 9 liter jug. 9L - 5  4L - 4

3. Empty the 4 liter jug into the pool.          9L - 5  4L - 0

4. Fill 4 liter jug again from the 9 liter jug.   9L - 1  4L - 4

5. Empty the 4 liter jug into the pool           9L - 1  4L - 0

6. Transfer 1 liter left 9L jug into the 4L.     9L - 0  4L - 1

7. Fill the 9 liter jug from the pool.             9L - 9  4L - 1

8. Fill up the 4 liter jug from the 9 liter jug. 9L - 6  4L - 4

That's how we have exactly 6 liters of water in 9 liters jug. 

Make it 50-50 in Two!

You have three jugs:

A 10-liter jug, filled with water
A 7-liter jug, empty
A 3-liter jug, empty

Your objective is to end up having 5 liters of water in the 10-liter jug, and 5 liters of water in the 7-liter jug.

Note that you have nothing else at your disposal other than these three jugs and that you cannot perform measurements by eye or based on the shape of the jugs.

THIS is how it can be done! 

Making it 50-50 in Two!

What was the challenge?

Let us label the 10-liter jug as A, the 7-liters jug as B, and the 3-liters jug as C.

 
STEPS : 

1]  Pour Jug A into Jug C.      A : 7    B : 0    C : 3
 
2]  Pour Jug C into Jug B.      A : 7    B : 3    C : 0

3]  Pour Jug A into Jug C.      A : 4    B : 3    C : 3

4]  Pour Jug C into Jug B.      A : 4    B : 6    C : 0

5]  Pour Jug A into Jug C.      A : 1    B : 6    C : 3

6]  Pour Jug C into Jug B.      A : 1    B : 7    C : 2

7]  Pour Jug B into Jug A.      A : 8    B : 0    C : 2

8]  Pour Jug C into Jug B.      A : 8    B : 2    C : 0

9]  Pour Jug A into Jug C.      A : 5    B : 2    C : 3

10] Pour Jug C into Jug B.     A : 5    B : 5    C : 0

Task Completed.

The Poisonous Glass?

You are given 4 identical glasses, completely filled with transparent, odorless liquids. Three of the liquids are pure water, and the fourth is poison, which is slightly heavier. If the water glasses weigh 250 grams each, and the poisoned glass weighs 260 grams, how can you figure out which one is which, using a measuring scale just once?

Here is the process to identify the poisonous glass!

Identifying The Poisonous Glass!

What was the challenge?

Let's number the 4 glasses as 1,2,3 and 4.

Here are steps to identify the glass with poisonous liquid in it. 

1. Empty the glass 1 into another empty glass.

2. Take about 1/4th liquid from glass 2 and pour it into emptied glass 1.

3. Take 3/4th of liquid from glass 3 and pout it into glass 1.

Now, glass 1 has 1/4th of liquid from glass 2 and 3/4th from glass 3.

4. Now put glass 1 and glass 4 on the measuring scale.

    4.1 - If it weighs exactly 500 gm then it suggests that glass 1 had poison.
  
    4.2 - If it weighs between 500 - 505 grams (precisely 502.5 if exactly 1/4th of liquid was taken from glass 2 to glass 1) then obviously glass 2 is with poisonous liquid.

    4.3 - If it weighs between 505 - 510 grams (precisely 507.5 if exactly 3/4th of liquid was taken from glass 3 to glass 1) then obviously glass 3 is with poisonous liquid.

    4.4 - If it weighs exactly 510 gm then it suggests that glass 4 has poison.

 

Mixed up Apples at the Farm

Someone has mixed up the apples. Read carefully what has happened. Can you find a way to help solve the problem.

• There are 10 baskets containing apples.

• There are various amounts of apples in each basket ranging from 10 to 20.

• 9 of the baskets contain apples weighing 4 ounces each.

• 1 of the baskets contains apples weighing 5 ounces each.

• All the apples look the same.

• The equipment you have is a set of scales and an empty basket.

• It is late and the truck is waiting to take the apples to market. You only have time to make one measurement using the scales. 

Take out the basket contains apples weighing 5 ounces each.

Here is how you can identify that basket! 

Source 
  

Sorting of Mixed Up Apples

How they were mixed?

Let's number all the baskets from 1 to 10. Just take out 1 apple from first basket, 2 from second, 3 from third & so on. We would have 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = 55 apples now. If each of them was of 4 oz, then these 55 apples together would have weighed as 55 x 4 = 220 oz. Since 1 basket have apples each weighing 5 oz, these 55 apples would weigh more than 220 oz.

Let's say it weighs 222 oz, then the 2 apples taken by second basket must be of 5 oz each. And if it weighs 228 then there are 8 apples weighing more than 4 oz (i.e. 5 oz each). Hence that eight basket must have all apples weighing.

So depending on how much weight of 55 apples exceeds 220 oz, we can identify the basket with apples weighing 5 oz each.  

 

Water Measurement With 2 Buckets - Puzzle

You have two buckets. One holds exactly five gallons and the other three gallons. How can you measure exactly four gallons of water into the five gallon bucket?

Assume you have an unlimited supply of water and that there are no measurement markings of any kind on the buckets.

How to measure 4 gallons?

Click here to know how it could be done? 

Source 

Water Measured Using 2 Buckets - Puzzle Cracked

What was the challenge? 

Method 1 :

1. Fill up the 3 gallons bucket & pour into 5 gallons bucket.

2. Again fill the gallon bucket & once again pour it into 5 gallons bucket. After completely filling 5 gallons bucket there will be 1 gallon left in 3 gallons bucket.

3. Empty 5 gallons bucket.

4. Pour that 1 gallon into 5 gallons bucket. Now fill up 3 gallons bucket. We have 4 gallons of water now 1 in 5 gallons bucket & 3 in 3 gallons bucket.


Method 2:

1. Fill up 5 gallons bucket & pour it into 3 gallons bucket. 2 gallons would remain in 5 gallons bucket.

2. Pour that 2 gallons of water into 3 gallons bucket. Now only space for 1 gallon left in 3 gallons bucket.

3. Again fill up 5 gallons bucket & pour into 3 gallons bucket containing 2 gallons of water left. So only 1 gallon can be poured & 4 gallons would be remaining in 5 gallons bucket.