Measuring 6L water from 4L and 9L buckets | Puzzles for Interview - Interview Preparation PDF Download

Introduction

Imagine you are given two buckets – one with a 4L capacity and the other with a 9L capacity. But here’s the catch – the buckets have no measurement lines on them. How would you measure exactly 6L of water using only these buckets and as much extra water as you need?

Solution

Step 1: Fill the 9L Bucket

Begin by filling the 9L bucket with water until it is completely full. This means the 9L bucket will have 9L of water in it, while the 4L bucket remains empty.

Step 2: Fill the 4L Bucket

Next, pour the water from the 9L bucket into the 4L bucket until it is completely full. This means the 4L bucket will now have 4L of water in it, while the 9L bucket has 5L of water remaining.

Step 3: Empty the 4L Bucket

Empty the water from the 4L bucket, leaving it completely empty. The 9L bucket still has 5L of water in it.

Step 4: Repeat Twice

Repeat the process of pouring water from the 9L bucket to the 4L bucket and emptying the 4L bucket twice more. This means that after three repetitions, the 4L bucket will have 1L of water in it, while the 9L bucket has 3L of water remaining.

Step 5: Pour 1L of Water into the 4L Bucket

Now pour the 1L of water remaining in the 9L bucket into the 4L bucket. This means the 4L bucket now has 1L of water in it, while the 9L bucket is completely empty.

Step 6: Refill the 9L Bucket

Refill the 9L bucket with water until it is completely full. This means the 9L bucket now has 9L of water in it, while the 4L bucket still has 1L of water in it.

Step 7: Pour Water into the 4L Bucket

Finally, pour water from the 9L bucket into the 4L bucket until it is completely full. This means the 4L bucket now has 4L of water in it, while the 9L bucket has 6L of water remaining, which is the desired amount.

Conclusion

By following these seven steps, you can measure exactly 6L of water using only a 4L and 9L bucket. This is a great example of problem-solving and critical thinking skills.